Ursidae

Question 1

Describe the ursid renal anatomy

Answer 1

Reniculate/lobular (F8)

Question 2

Ursid mammae location

Answer 2

Pectoral (F8)

Question 3

Describe diet of ursid species

Answer 3

Omnivores - all except polar bear and giant panda, Carnivore - polar bear, Bamboo - giant panda (F8)

Question 4

Which species is uniquley susceptible to CDV

Answer 4

Giant panda (no clinical signs in polar bears) (F8)

Question 5

What are the clinical signs of canine adenovirus 1 in bears?

What are the typical inclusion bodies?

Answer 5

anorexia, lethargy, hindlimb ataxia, neuro (seizures, paralysis) (F8)

Zoo Path

• Canine adenovirus 1 – Infectious canine hepatitis; has been isolated from captive ABB exposed to canids.
  
  • CS – Anorexia, lethargy, hindlimb ataxia, seizures, paralysis, corneal opacity, death despite hx vaccination.
  • Survivors have persistent neuro signs and lethargy for months.
  • Serologic prevalence in NA brown bears ~15% samples.
  • Also found in captive and giant pandas in China.
  • Exposure to domestic dogs one potential source.
  • Also reported in Malayan sun bears, brown bears, polar bears.
  • Skunks and raccoons within and near exhibits have been suspected sources.
  • Inclusions – intranuclear viral inclusion bodies.
    
    • DNA viruses usually intranuclear.

Question 6

Equine herpes - which EHV has been shown to cause disease in polar bears? Which in black bears?

Answer 6

EHV9 in polar bears, EHV1 in am black bear (F8)

Question 7

Vectors for EHV infection?

Answer 7

Equids (zebra), rodents (F8)

Question 8

Sun bear with oral SCC - what virus is associated?

Answer 8

Ursid herpesvirus 1 (F8)

Question 9

Clinical signs of WNV in Ursids

Answer 9

Acute onset progressive nonambulatory paraparesis (F8)

Question 10

Causative agent of salmon poisoning?

Answer 10

Neorickettsia helminthoeca (F8)

Question 11

Small white granules on the ventral surface of the tongue of a polar bear - differential?

Answer 11

Trichinella (F8)

Question 12

Green discoloration of polar bear haircoat causes?

Answer 12

Growth of cyanophyte (blue-green algae) wihtin unpigmented hollow shafts of guard hairs (F8)

• Green discoloration of hair coat.
  
  • Unique to captive PB.
  • Cyanophyte (BG algae) within the unpigmented, hollow shafts of guard hairs.
  • Yellow discoloration from sebaceous secretions may also occur.
  • Hair shafts of affected bears have lateral ducts connected to the medulla that are not present in unaffected bears.
    
    • Not clear if lateral ducts are the cause or the result of the algae.
    • Control – salt-water tx, peroxide baths, water tx measures to reduce presence of algae in water.

Question 13

Most common neoplasms in bears?

Answer 13

Hepatobilliary neoplasia (especially sloth bear and sun bear) (F8)

Question 14

Which bear species gives birth throughout the year with NO delayed implantation

Answer 14

Sun bear (F8)

Question 15

Clinical signs of GM1 - gangliosidosis in free ranging black bears?

What is the underlying etiology?

Answer 15

poor bcs, intention tremor of head, ataxia, hypermetria (ZP)

Decreased beta-galactosidase-1 gene (suggests heritable) (ZP)

Question 16

Pathologic change of CDV infection/area of brain affected?

Answer 16

White matter demyelination - cerebellum most severely (ZP)

Question 17

Zoonotic disease transmitted by eating infected bear meat?

Answer 17

Trichinella spiralis (ZP)

Question 18

Special anatomic adaptations in giant panda and andean bear?

Answer 18

Epicondylar foramen in distal humerus and false thumb (enlarged radial sesamoid) F9

Question 19

What is the typical signalment of spectacled bear alopecia sydnrome?

What are the typical clinical signs?

What is the recommended treatmetnt?

Answer 19

Captive females (F9)

Patchy alopecia over dorsum and flank –> puritis –> alopecia of face and extremities –> generalized full body alopecia (F9)

Apoquel (oclacitinib maleate) - inhibis pro-inflammatory cytokines (F9)

Question 20

What are the clinical signs of spirometra in bears?

Answer 20

Long slender parasite –> irregular yellowish cysts in subcutaneous tissue and muscle fascia. Bear is paratenic host (SCWDS)

Question 21

What is the ascarid roundworm of bears?

Answer 21

Baylisascaris transfuga - not known to be pathogenic to bears, not known to be human pathogen (SCWDS)

• GI nematodes.
  
  • Ascarids very common.
  • Baylisascaris transfuga.
    
    • Large worms can cause intestinal obstruction, poor BCS.
    • Reinfection after tx common.
    • Ova not destroyed by routine cleaning.
    • Can remain infective in soil for years.

Question 22

What is the ursid demodex mite?

Answer 22

Demodex ursi (SCWDS)

Question 23

Clinpath changes seen in bears caught in culvert traps?

Answer 23

Hemoconcentration (West)

Question 24

What is a potential side effect seen in bears caught in snare traps?

Answer 24

Capture myopathy (West)

Question 25

Which anesthetic protocols have been associated with sudden recoveries and is not recommended for brown or polar bears?

Answer 25

Xylazine-ketamine and medetomidine- ketamine (West)

Question 26

What is the recommended dart site for polar bears?

Answer 26

Shoulder or neck (West)

Question 27

Denning associated alopecia seen in what species? Where does this alopecia typically occur?

Answer 27

Free ranging black bears - alopecia around eyes, muzzle, neck, thorax (ZP)

Question 28

What is the typical signalment for polar bears that develop bilateral symmstric alopecia?

Answer 28

Males and subadults more often affected, affected bears have lower BCS (ZP)

Question 29

A recent study described the effects of housing on Andean bear alopecia syndrome.

What did they find?

Answer 29

Van Horn, R. C., Sutherland-Smith, M., Bracho Sarcos, A. E., Thomas, G., Shanks, J. A., & Owen, M. A. (2019).

The Andean bear alopecia syndrome may be caused by social housing.

• Zoo biology*, 38(5), 434-441.
• Abstract:* The Andean bear alopecia syndrome is a progressive and chronic condition documented in ex situ populations. Recent advances focus on treating symptoms, not preventing future cases. We therefore explored the epidemiology of this syndrome through an analysis of husbandry and veterinary conditions of 63 Andean bears (26M:37F) housed in North and South American zoos and other ex situ circumstances. We had the most complete information for the North American population and found that 29% of females (n = 24) were affected. No males (n = 26) were affected. An analysis of generalized linear models indicated that three models were competitive in describing the occurrence of the condition (i.e., ΔAICc ≤ 2): the model including only the individual’s sex (χ2 = 13.41, df = 1, p<.001), the model including both individual sex and social housing status (χ2 = 1.36, df = 2, p < .001), and the model including both individual sex and the expression of stereotypical behaviors (χ2 = 13.82, df = 2, p = .001). Stereotypical behaviors were common among both males (50%, n=26) and females (51.9%, n = 27) whether or not they were affected, but the syndrome was seen only in females who had been socially housed. Therefore, we suggest that the Andean bear alopecia syndrome is a symptomatic response to the long‐term social housing of bears that would otherwise not live socially. To prevent new cases, we recommend that female Andean bears be housed with adult conspecifics only when females choose to cohabitate.
• Andean bear alopecia syndrome – unk etiology – characterized by chronic, progressive hair loss
  
  • Typically on face (periocular) and caudal lumbar region resulting in bilaterally symmetric alopecia, mucopurulent ocular discharge and conjunctivitis can also be seen
  • Higher prevalence in females
  • Symptoms being spring/summer and abate fall/winter
• Possible endocrine cause in female bears housed together
• Take Home Message:* Andean bear alopecia syndrome is most common in female bears and may be due to social housing of a typically asocial animal
• References:*
• Drake, G. J., Nuttall, T., López, J., Magnone, W., Leclerc, A., Potier, R., … Cosgrove, S. B. (2017). Treatment success in three Andean bears (Tremarctos ornatus) with Alopecia syndrome using oclacitinib maleate (Apoquel®). Journal of Zoo and Wildlife Medicine, 48, 818–828.
• Nicolau, A., Lemberger, K., Mosca, M., Leclerc, A., Lécu, A., & Pin, D. (2018). Clinical and histopathological aspects of an alopecia syndrome in captive Andean bears (Tremarctos ornatus). Veterinary Dermatology, 29, 234–e85.

Question 30

A recent study modified temperature and photoperiod to mimic seasonality. How did this affect the reproductive behavior of giant pandas?

Answer 30

Tay, T. T., Li, D., Huang, Y., Wang, P., Tahar, T., & Kawi, J. (2018).

Effects of changes in photoperiod and temperature on the estrous cycle of a captive female giant panda (Ailuropoda melanoleuca).

Zoo biology, 37(2), 90-97.

Abstract:

The female giant panda’s estrus is known to be photoperiod sensitive, triggered by increasing day length. A pair of giant pandas was brought to Singapore in September 2012 and exposed to a constant temperature and photoperiod during the first 2 years. The female did not show any signs of estrus during that period. In November 2014, photoperiod and temperature were manipulated to simulate seasonal changes, to investigate the effects of environmental factors on the sexual behavior of the giant pandas. This paper documents the changes and observations carried out from 2012 to 2016, in the attempt to breed this vulnerable species.

Key Points

• Seasonally monoestrus (Feb – June) with estrous cycle seeming sensitive to photoperiod changes
• Singapore day length is 12hr year round while China sees 4hr difference with seasons
• Behaviors were monitored and urine estrogen was evaluated with enzyme immunoassays
• Photoperiod and temperature were manipulated to stimulate winter and summer
  
  • Behavioral changes were displayed (dec appetite, restless, scent marking, bleating, playing with water) and male interest
  • Vulva became progressively swollen
  • Urinary estrogen levels increased

Take home: photoperiod and temperature play role in panda reproduction

Question 31

A recent study evaluated trace nutrients in giant panda serum.

What are the health benefits of the following micronutrients?

• retinol
• vitamin D
• alpha tocopherol (vitamin E)
• cobalt
• copper
• iron
• magnesium
• molybdenom
• selenium
• zinc

How did the findings in this study compare to those previously done?

Answer 31

Cutler, D. C., Bissell, H., Wang, C., & Rivera, S. (2019).

Serum trace nutrient values in four captive giant pandas (ailuropoda melanoleuca).

Journal of Zoo and Wildlife Medicine, 50(1), 176-182.

Abstract: Trace nutrients have been shown to play important health roles in both domestic and wild animals, but there has been little investigation into their values and effects in giant pandas (Ailuropoda melanoleuca). The goal of this study was to obtain serum vitamin and mineral values in a group of healthy, captive giant pandas (n = 4). Twenty-seven samples were obtained from the group from 2008 to 2012. Serum analytes measured included retinol, α-tocopherol, hydroxyvitamin D, cobalt (Co), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), selenium (Se), and zinc (Zn). The diet was evaluated for protein, fat, fiber, Ca, P, magnesium (Mg), potassium (K), sodium (Na), Fe, Zn, Cu, Mn, and Mo. Comparison with other giant panda nutrient values were made. Further research with increased sample sizes and different populations are warranted.

• Retinol (vit A) – Role in rate of mitosis and cellular differentiation.
• Vid D – Ca and P homeostasis.
• Alpha tocopherol (vit E) – antioxidant.
• Cobalt (Co) – Component of vit B12, enzyme involved with carbon skeleton rearranging within the cell.
• Copper (Cu) – Role in enzymatic processes including cellular respiration, bone formation, cardiac function, connective tissue development, SC myelination, tissue keratinization and pigmentation.
• Iron (Fe) – Important molecular component of many biological processes including oxygen transport in blood, cellular enzymes.
• Mn – Integrated into certain metalloenzymes or active other enzymes, functiton of bone growth, reproduction, lipid and carbohydrate metabolism, cellular structure, immune function, brain function.
• Molybdenum (Mo) – Part of several enzymes, necessary for production of cellular components (purines, pyrimidines, pteridines, aldehydes).
• Se – Essential component of glutathione peroxidase, antioxidant activity within cells.
• Zn – Enzymatic processes, necessity for protein-binding to DNA.
• Appropriate dietary trace nutrient requirements of giant panda not described.
• Diet – bamboo supplemented with commercial herbivore biscuit and produce. No supplements.
• Possible role of iodine deficiency in reproductive failure in giant pandas.
• Mucous-like stools not observed in wild pandas, likely diet related.
• Serum alpha tocopherol in this group of pandas higher than previously noted in other panda studies. Co lower vs previous studies, ause unknown. Mn lower vs previous reports. Se higher than other studies. Vit D levels much lower vs other ursids and canids.
• Takeaway: Small sample size, more studies needed. Pandas might have lower vit D compared to other ursids, unknown.

Question 32

A recent study described the anesthetic protocols used in andean bears, sloth bears, and giant pandas.

What was the most commonly used protocol?

What were some of the most common adverse events?

Was metoclopramide effective in preventing emesis?

Answer 32

Journal of Zoo and Wildlife Medicine 51(1): 67-79, 2020

REVIEW OF ANESTHETIC PROTOCOLS IN ANDEAN BEARS (TREMARCTOS ORNATUS), SLOTH BEARS (MELURSUS URSINUS), AND GIANT PANDAS (AILUROPODA MELANOLEUCA) AT THE SMITHSONIAN INSTITUTION’S NATIONAL ZOOLOGICAL PARK, 1995–2016

Michael S. McEntire, DVM, Katharine L. Hope, DVM, Dipl ACZM, Lee-Ann C. Hayek, PhD, and Jessica L. Siegal-Willott, DVM, Dipl ACZM

Abstract:  A review of anesthetic procedures used in Andean bears (Tremarctos ornatus), sloth bears (Melursus ursinus), and giant pandas (Ailuropoda melanoleuca) housed at the Smithsonian Institution’s National Zoological Park (NZP) from 1995 to 2016 was performed. A total of 146 anesthetic procedures (55 procedures on 12 Andean bears, 38 procedures on nine sloth bears, and 53 procedures on five giant pandas) occurred at NZP during this time frame. Induction protocols involved some combination of ketamine (K; n=121), tiletamine– zolazepam (TZ; n=91), medetomidine (M; n=67), xylazine (X; n=42), midazolam (Mid; n=9), and butorphanol (B; n=1). The most commonly used protocols were TZKM for both Andean bears (n =29) and sloth bears (n=12), and KX in giant pandas (n=17). Supplemental injections of K, TZ, Mid, or M were required to complete inductions in 66 cases (45%). Anesthetic maintenance was most often completed with isoflurane, ketamine, or propofol. The most commonly reported complications included perianesthetic emesis (n=47), ptyalism (n=16), and seizure-like activity (n=11). The most frequent physiologic findings included low pulse oximetry values (n=95), bradycardia (n=95), hypothermia (n=74), and hypertension (n=55). Dose ranges, induction, and recovery times, supplementation and complication rates, and physiologic values are reported for each protocol by species.

Key Points

• Twelve different induction protocols
• Andean bears had significantly longer induction time than other two species, despite similar dosing
• Induction times were longer and more variable in unhealthy bears (ASA status >3)
• Older bears (sloth bears and giant pandas) had longer inductions; no Andean bear age difference
• Intubation: 56% sloth bear, 45% Andean bear, and 36% giant panda procedures
• Induction supplementation needed in less than half of the procedures
  
  • Intra-adipose or SQ injection not IM, bear overexcitation, or weight underestimation
• Tachycardia with Telazol and/or ketamine without an alpha-2 agonist
• Bradycardia with almost all alpha-2 agonist protocols, seen in all three species
• Hypothermia in half the procedures; each induction protocol and species
• Hypertension seen with alpha-2 protocols
• Apnea seen in low numbers with TZKM for induction with isoflurane maintenance
• All alpha-2 agonist protocols reversed; no difference in recovery times by protocol, age, sex, species, supplementation, or health status
• Majority of emesis seen during recovery; each protocol with alpha-2 had reported emesis
  
  • Emesis reported in 55% of procedures where metoclopramide was administered
• Seizures seen in protocols with ketamine; combated with midazolam or isoflurane
• No spontaneous arousals reported
• Supplemental oxygen should be provided to anesthetic ursids via nasal cannula or intubation

Take home: TZKM most commonly used; emesis, ptyalism, seizures, hypoxemia, bradycardia, hypothermia, and hypertension seen; metoclopramide not effective prevention for emesis

Question 33

A recent study described guaifenesin-ketamine-medetomidine CRIs in American black bears.

How was the CRI prepared?

What were the bears initially immobilized with?

What was the rate?

What were some of the physiologic effects of the protocol?

How effective was the anesthesia?

What is a potential use of this protocol?

Answer 33

Siegal-Willott, J. L., Bauer, K. L., Hayek, L. A. C., Luensman, N. M., Cross, T. N., Sajecki, J. L., & McRuer, D. L. (2019).

Comparison of isoflurane gas versus a guaifenesin, ketamine, and medetomidine constant-rate infusion for maintenance anesthesia in american black bears (ursus americanus).

Journal of Zoo and Wildlife Medicine, 50(3), 570-578.

Abstract: Published anesthetic protocols for captive and free-ranging bears are limited to injectable inductions with maintenance via inhalants or additional injectable boluses. Though common in other species, intravenous (IV) continuous-rate infusions (CRI) using guaifenesin combinations have not been evaluated in ursids. This study evaluated the use of a CRI compared to an inhalant for maintenance anesthesia. Seven healthy American black bears (Ursus americanus) were anesthetized in a crossover design with two different anesthetic maintenance protocols. Bears were immobilized with ketamine (2.02 ± 0.14 mg/kg) and medetomidine (0.04 ± 0.003 mg/kg) for both protocols. The anesthetic maintenance control protocol consisted of isoflurane gas (ISO) started at 2% delivered by endotracheal tube; the experimental protocol consisted of guaifenesin, medetomidine, ketamine (GMK) IV CRI started at 50 mg/kg/hr guaifenesin, 0.01 mg/kg/hr medetomidine, and 1 mg/kg/hr ketamine. Induction and recovery parameters including time to first effect, recumbency, and hands on; duration of maintenance protocol; and time from reversals administered to head up, standing on all four feet, no ataxia, and to fully recovered were recorded and compared between protocols. Heart rate, respiratory rate, rectal temperature, blood pressure, end tidal carbon dioxide, and hemoglobin oxygen saturation were recorded at 5-min intervals and compared between protocols. Venous blood gases were obtained at the start, middle, and end of the maintenance anesthesia and compared between protocols. All bears exhibited hypertension with mild respiratory acidosis throughout procedures. Measured physiologic parameters did not differ significantly between the isoflurane and the GMK CRI maintenance protocols, with the exception of higher endpoint (ISO) pCO2 measurements. No adverse events were recorded with either protocol, and adequate depth of anesthesia was maintained with both protocols. GMK CRI provides a safe, effective, and more portable alternative to inhalant anesthetics for maintenance anesthesia in bears in captivity or in the field.

• CRI prepared with 1000 mg ketamine and 10 mg medetomidine to a 1 L bag of 50 mg/mL guaifenesin solution
• Light anesthetic plane maintained in both – GMK bears had palpebral reflex throughout
• Guaifenesin – centrally acting muscle relaxant, doesn’t produce analgesia or unconsciousness
• Emesis did not occur in any bears

Take home: GMK produces light surgical anesthesia in field settings

Question 34

A recent study compared the use of ketamine-xylazine to butorphanol-azaperone-medetomidine protocols in American black bears.

What are some of the benefits of BAM over KX?

What is azaperone?

What were some of the observed physiologic effects of these protocols?

Answer 34

Williamson, R. H., Muller, L. I., & Blair, C. D. (2018). The use of ketamine-xylazine or butorphanol-azaperone-medetomidine to immobilize american black bears (ursus americanus). Journal of wildlife diseases, 54(3), 503-510.

Abstract: Wildlife anesthetic protocols must offer rapid inductions and recoveries, be physiologically safe, and be minimally regulated. With this in mind, we evaluated differences in induction and recovery times and physiological parameters in 33 American black bears (Ursus americanus) anesthetized with ketamine-xylazine (KX) or immobilized with a commercial drug combination of butorphanol, azaperone, and medetomidine (BAM). Dose was based on mass estimated from field observations. Bears were housed at Appalachian Bear Rescue, Townsend, Tennessee, US, or free-ranging within the Great Smoky Mountains National Park (Tennessee and North Carolina, US) and chemically immobilized for management purposes. From 11 April to 29 June 2016, we immobilized bears with injection via pole syringe or disposable dart projected from an air-powered dart rifle. Once immobilized, we measured each bear’s temperature, respiration (breaths/min), heart rate (beats/min), hemoglobin oxygen saturation (via pulse oximetry), arterial blood gases, and mass (kg). We found no differences in the induction parameters, partial pressures of CO₂, and rectal temperatures. The BAM-treated bears had lower heart and respiratory rates that led to lower hemoglobin oxygen saturation levels (from blood gas analysis, SaO₂). The SaO₂ after treatment with BAM (91.1±0.8%) was lower than with KX (93.4±0.9%). After handling, we reversed KX-treated bears with a x̄=0.2±0.02 mg/kg yohimbine and BAM-treated bears with x̄=1.5±0.1 mg/kg atipamezole and 0.8±0.1 mg/kg naltrexone. We found no differences in the recovery times to increased respiration and to the bear assuming a head-up position. The BAM-treated bears stood and recovered quicker than did KX-treated animals. Based on our observations, BAM appears to offer safe, predictable immobilizations with fewer drawbacks and faster recovery times than KX-treated bears.

Key Points

• Butorphanol, azaperone, medetomidine (BAM).
  
  • Reliable and reversible anesthesia in black bears.
  • Butorphanol is regulated, AM are not.
  • B and M reversible (naltrexone, atipamezole).
  • Cost effective, potent in small volumes.
  • BAM act synergistically on CNS.
    
    • Butorphanol mild sedation and analgesia alone.
    • In combination with alpha 2, profound sedation.
  • Azaperone – butyrophenone.
    
    • Combined with opioid or cyclohexane produces smoothing effects that shorten induction and reduce primary immobilizing agent.
  • Medetomidine may cause hypoxemia and bradycardia.
• This study: Compare immobilization with KX and BAM on induction time, recovery time, physiological effects to determine best option for immobilizing American black bears in the field. Also compared hemoglobin O2 sat by arterial blood gas and pulse ox.
  
  • 24 yearling black bears at Appalachian Bear Rescue Facility, TN.
  • Darted or pole syringed IM.
  • Immobilized with 6.6 mg/kg ketamine, 3.3 mg/kg xylazine or commercial BAM that contained 0.6 mg/kg butorphanol, 0.2 mg/kg azaperone, 0.2 mg/kg medetomidine.
• Results:
  
  • 66% KX bears required one injection, others required additional drugs for ax depth.
    
    • 4 BAM treated bears (26%) required additional drugs.
  • Mean HR lower in BAM tx bears (~54 vs 95 BPM).
    
    • RR lower for BAM tx bears and irregular with periods of apnea.
  • SaO2 slightly lower for BAM tx bears (91% vs 94%).
    
    • Bears treated with BAM considered mildly hypoxemic.
  • No difference in pCO2 or rectal temperature.
  • General agreement on hemoglobin O2 sat for both methods (pulse ox and arterial blood gas).
  • Time to standing after reversal and total recovery were faster for bears treated with BAM than with KX. (Reversals administered for both protocols).
• Discussion
  
  • Overdose with BAM by about 40% based on estimated weights vs actual weights.
    
    • Still considered to be safe and effective.
    • May have contributed to hypoxemia.
  • No bears received supplemental O2.
  • Advantages of BAM over KX:
    
    • Lower volume for darting, faster recovery after handling, lower DEA schedule.
  • One bear required an additional half atipamezole dose about 20 min after initial reversal with BAM, authors recommend doing this if recovery is prolonged.
  • Bears in this study may have had unnatural layers of adipose for their age class due to being in rehab setting vs wild bears.
  • Found a lot of variability with readings with the pulse oximeter – some bears couldn’t read on the tongue, tried labia or prepuce with variable success.

Question 35

A recent study evaluated the use of nalbuphine-medetomidine-azaperone protocols in American black bears.

What are some of the benefits of this protocol in a field situation?

What physiologic effect was noted with this protocol? How was it addressed?

Was SpO2 an adequate measure of oxygenation?

Answer 35

Wolfe, L. L., Wood, M. E., Fisher, M. C., & Sirochman, M. A. (2019).

Evaluation of chemical immobilization in captive black bears (ursus americanus) receiving a combination of nalbuphine, medetomidine, and azaperone.

Journal of wildlife diseases, 55(1), 84-90.

Abstract: To assess potential seasonal differences in responses to immobilization, we sedated eight orphaned yearling black bears (Ursus americanus) being held for rehabilitation at a wildlife facility in Colorado, US, using a premixed combination of nalbuphine (40 mg/mL), azaperone (10 mg/mL), and medetomidine (10 mg/mL; NalMed-A) in October (autumn) prior to hibernation and again after emergence in May (spring) prior to their release. We dosed all bears at 1 mL NalMed-A per estimated 45 kg body mass (1 mL NalMed-A/45 kg), delivered by intramuscular injection using a pole syringe, to facilitate routine examination and ear tagging. Arterial blood gases were measured to assess oxygenation and acid-base status of bears both pre and post oxygen supplementation. The mean (SE) dose calculated post hoc was 0.9 (0.04) mg nalbuphine/kg, 0.2 (0.01) mg azaperone/kg, and 0.2 (0.01) mg medetomidine/kg. The mean induction time was 8 (1) min for six of the bears in October and 6 (1) min for eight bears in May. The NalMed-A combination provided good sedation in captive yearling black bears in autumn and spring and was effectively antagonized with a combination of naltrexone and atipamezole. Mild hypoxemia (PaO₂: 53.5−54.4 mmHg) was the most significant side effect and was corrected (PaO₂: 68.4−150.1 mmHg) with supplemental oxygen administered at 2−5 L/min for 5 min (point of sampling).

Key points:

• Most ursid sedation protocols in bears combine dissociatives with alpha 2’s
• This study evaluated Nalbuphine (opioid), medetomidine (alpha 2), and azaperone (neuroleptic) as a protocol for sedation of black bears—more reversible and no controlled drugs, potentially more available and useful for fieldwork.
• Blood gas (arterial) collected before O2 supplementation and again 5 mins after starting
• O2 delivered by nasal cannula. Higher flow rate used during second sedation event
• Hypoxemia noted prior to O2 supplementation at both handling events, but effectively corrected by both rates of O2 supplementation. Response was better in May, suspected due to longer nasal catheter rather than higher flow rate
• SPO2 did not accurately reflect PaO2 (though was not taken continuously), was consistently low

Takeaway: NalMed-A provided reversible, good-quality sedation with a low delivery volume in captive black bears. Hypoxemia was a side effect in some individuals and we recommend oxygen supplementation for bears and other species immobilized with this drug combination.

Question 36

A recent study surveyed institutions housing Giant Pandas to assess prevalence of ocular issues.

What part of the eye was most commonly affected? What are potential etiologies for this?

What was the second most common ocular issue?

Answer 36

Miller, S., Whelan, N., Hope, K., Marmolejo, M. G. N., Knightly, F., Sutherland-Smith, M., & Rivera, S. (2020).

Survey of clinical ophthalmic disease in the giant panda (ailuropoda melanoleuca) among north american zoological institutions.

Journal of Zoo and Wildlife Medicine, 50(4), 837-844.

Abstract: This study surveyed six North American zoologic institutions to collect retrospective information on the incidence of ocular disease in the giant panda. Reported information included sex and age at presentation, as well as diagnosis, treatment, duration, and clinical outcome for each episode of ocular disease. Among the 42 animals included in the survey, 10 (23.8%) had clinical ocular abnormalities reported. Multiple disease episodes were reported in four animals, with 20 clinical episodes, and one additional animal who presented with corneal scarring from historic keratitis. Age at presentation varied from 0.4 to 26 yr (mean, 11.8 yr; median, 10.4 yr). Corneal abnormalities (including corneal opacity or haze, keratitis, corneal ulcers, and bullous keratopathy) were the most common pathologies reported, followed by conjunctivitis and/or ocular discharge. Additional reported abnormalities included limbal squamous cell carcinoma and lipid degeneration. Six cases resolved without intervention. Treatment protocols included topical and/or systemic medication with or without surgical intervention, which commonly resulted in resolution with or without persistent corneal scar. The prevalence of ocular disease identified in the giant panda in this study is higher than previous publications surveying ocular disease in the family Ursidae, indicating that this is an important source of morbidity in this species.

• Reviews of disease in giant pandas have shown GI disease, abdominal effusions, dental disease as top causes of morbidity and mortality.
• Relatively high incidence of ocular disease in this study compared to family Ursidae in other studies. Sunbears had the highest prevalence of ocular disease in another study.
• Cornea most commonly affected – Inflammatory and noninflammatory keratopathies, anterior uveitis, glaucoma may contribute to corneal opacities. Environmental factors/UV radiation may play a role.
  
  • Inciting etiologies for keratitis – Trauma, immune mediated, infectious, neoplastic.
  • Indolent ulcers – Abnormal superficial stroma and lack of adhesion complexes within basement membrane.
  • Bullous keratopathy – Corneal edema resulting in formation of subepithelial and/or stromal bullae. Endothelial dz or trauma results in fluid accumulation in the stroma.
• Conjunctivitis and/or ocular discharge second most-reported in this study.
  
  • Infectious vs environmental irritants, contact hypersensitivity/allergy, tear deficiency.
• Takeaway: In a retrospective study of NA zoo institutions, corneal disease was the most common type of ocular dz in pandas, and ocular dz had a higher prevalence vs previous reports in Ursids.

Question 37

A recent study evaluated the exposure of Alaska brown bears to various pathogens over time and location.

What pathogens did they test for?

Seroprevalence of what virus was most common?

Seroprevalence to what pathogens were found at all locations?

What pathogens were not found in the youngest bears?

What was the prevalence of trichinella antibodies?

Answer 37

Ramey, A. M., Cleveland, C. A., Hilderbrand, G. V., Joly, K., Gustine, D. D., Mangipane, B., … & Yabsley, M. J. (2019).

Exposure of Alaska brown bears (Ursus arctos) to bacterial, viral, and parasitic agents varies spatiotemporally and may be influenced by age.

Journal of wildlife diseases.

Abstract: We collected blood and serum from 155 brown bears (Ursus arctos) inhabiting five locations in Alaska, US during 2013–16 and tested samples for evidence of prior exposure to a suite of bacterial, viral, and parasitic agents. Antibody seroprevalence among Alaska brown bears was estimated to be 15% for Brucella spp., 10% for Francisella tularensis, 7% for Leptospira spp., 18% for canine adenovirus type 1 (CAV-1), 5% for canine distemper virus (CDV), 5% for canine parvovirus, 5% for influenza A virus (IAV), and 44% for Toxoplasma gondii. No samples were seropositive for antibodies to Trichinella spp. Point estimates of prior exposure to pathogens among brown bears at previously unsampled locations generally fell within the range of estimates for previously or contemporaneously sampled bears in Alaska. Statistical support was found for variation in antibody seroprevalence among bears by location or age cohort for CAV-1, CDV, IAV, and T. gondii. There was limited concordance in comparisons between our results and previous serosurveys regarding spatial and age-related trends in antibody seroprevalence among Alaska brown bears suggestive of temporal variation. However, we found evidence that the seroprevalence of CAV-1 antibodies is consistently high in bears inhabiting southwest Alaska and the cumulative probability of exposure may increase with age. We found evidence for seroconversion or seroreversion to six different infectious agents in one or more bears. Results of this study increase our collective understanding of disease risk to both Alaska brown bear populations and humans that utilize this resource.

• Opportunistically collected and analyzed blood and serum samples from brown bears captured by state and federal agency personnel in AK 2013-2016.
• Tested for Brucella, F. Tularensis, Lepto, CAV-1, CDV, CPV, influenza A, T gondii, Trichinella.
• Antibodies to F. tularensis, CAV-1, CPV, T gondii were detected at all three sampling locations.
• CDV antibodies only identified at Gates of the Arctic NPP.
• Influenza A antibodies only found in Lake Clark NPP and Yakutat Forelands.
• Ab to trichinella were not identified at any location.
• Ab to Brucella, Lepto, CAV-1, and CDV detected in all age cohorts except youngest (2.5-4 yo).
• Overall antibody seroprevalence at these locations were relatively low and within range of estimates for other sampling locations.
  
  • Exceptions – Relatively high antibodies for Lepto (13%) and T gondii (59%) at Lake Clark NPP and IAV at Yakutat Forelands.
  • Statistically different seroprevalence of Ab to CAV-1 among sampling locations and age cohorts consistent with previous observations (highest at Kodiak Island, older bears). Suggests increasing cumulative exposure probability with age and that Kodiak Island may represent area where CAV-1 is endemic.

Takeaway: Ab to Trichinella not ID at any location. CAV-1 highest prevalence at Kodiak Island in older bears.

Question 38

A recent study evaluated the pathogen prevalence in American black bears in New Mexico.

What pathogens did they test for?

Which pathogens were most prevalent?

Which were not present?

Answer 38

JWD 2019 55(4): 745-754

PATHOGEN PREVALANCE IN AMERICAN BLACK BEARS (URSUS AMERICANUS AMBLYCEPS) OF THE JEMEZ MOUNTAINS, NEW MEXICO, USA

Abstract

Informed management of American black bears (Ursus americanus) requires knowledge of the distribution and pathology of diseases affecting the species. Little information is available on pathogen prevalence from black bear populations in the Southwest, US, and it is unknown how these infections may influence black bear populations or disease transmission. We captured New Mexico black bears (Ursus americanus amblyceps) during 2016–17 as part of a long-term monitoring project and opportunistically collected 36 blood samples from 12 female and 17 male black bears. We wanted to determine prior exposure to canine distemper virus, canine parvovirus, Yersinia pestis, Francisella tularensis, West Nile virus, Toxoplasma gondii, and the tick-borne pathogens, Anaplasma spp., Ehrlichia spp., Borrelia burgdorferi, Rickettsia spp., and Babesia spp. Approximately half (55%, 16/29) of the individuals sampled had antibodies to Y. pestis, and 37% (10/27) had antibodies to T. gondii. Prevalence of antibodies to West Nile virus, F. tularensis, and canine parvovirus were lower (i.e., 11, 10, and 3%, respectively). We detected no antibodies to canine distemper, B. burgdorferi, Rickettsia spp., or Babesia spp. We documented changes in antibody titer levels for both sexes of several recaptured black bears. Our data will inform managers of pathogen prevalence and distribution in black bears in north-central New Mexico and provide a vital baseline dataset for future pathogen monitoring. Additionally, these data support actions to minimize exposure through handling wild individuals or through hunter harvest activities.

Introduction

• Black bears are ideal pathogen sentinels as they are long lived and wide-ranging
• Often in contact with other wildlife populations, domestic animals, and humans
  
  • Black bear harvesting currently allowed in many states

Methods

• Prospective study: 36 blood samples from 29 clinically healthy black bears were opportunistically collected in north-central New Mexico from 2016-2017
• Goal: assess prevalence of disease exposure; provide baseline data for future work

Results/ discussion

• Canine distemper titer: all negative; Canine parvovirus titer: 3% (1 bear) positive
  
  • Parvo negative upon resampling (suspect false positive)
• Yersinia pestis titer: 55% positive
  
  • Southern Rockies has a high incidence of plague transmission
  • Potentially prey on infected rodents when food limited
• Francisella tularensis titer: 10% positive
• WNV titer: 11% positive
  
  • First report of WNV in a western black bear population
• Toxoplasma gondii titer: 37% positive
  
  • Zoonotic implications; regularly overlap with pumas and bobcats
• Tick-borne PCR panel: all negative for Borrelia burgdorferi, Rickettsia, and Babesia; 4% (1 bear) positive for Anaplasma and Ehrlichia

Question 39

A recent study evaluated the prevalence of leptospirosis in American black bears in North Carolina.

How is leptospirosis shed?

What are the most common carriers in the US?

Why are bears a potential model for human exposure?

How did prevalence vary between the MAT versus PCR? Why was that?

What serovar was detected? Does this pose a risk to domestic species?

Answer 39

Sasmal, I., Gould, N. P., Schuler, K. L., Chang, Y. F., Thachil, A., Strules, J., … & DePerno, C. S. (2019).

Leptospirosis in urban and suburban american black bears (ursus americanus) in western north carolina, usa.

Journal of wildlife diseases, 55(1), 74-83.

ABSTRACT: American black bear (Ursus americanus) populations in North Carolina, US have recovered significantly in recent decades and now occupy much of western North Carolina, including urban- suburban areas. We used the black bear as a potential sentinel for leptospirosis, a bacterial zoonotic disease caused by Leptospira spp., which is maintained by domestic and wild mammals. We determined whether Leptospira spp. were present across a gradient of housing densities in the urban and suburban black bear population in and around Asheville, North Carolina using serologic and molecular surveys. We collected blood from captured black bears (n=94) and kidneys and bladders from carcasses (n=19). We tested a total of 96 (47 females, 47 males, and 2 unknown) serum samples by microscopic agglutination test (MAT) and had positive results (titer .1:100) for L. kirschneri serovar Grippotyphosa (L. Grippotyphosa) in 4 females (8%) and 5 males (10%). No other serovars showed elevated titers in MAT. We tested a total of 125 samples using PCR (n=96 serum, n=20 kidney, and n=9 bladders) and obtained positive results from one serum (1%), one kidney (5%), and one bladder (11%). The presence of Leptospira spp. in black bears occupying an urban and suburban landscape may indicate a more extensive occurrence of the bacteria among animals in the study region because black bears are the top carnivore in that ecosystem. Potential threats of widespread contamination during natural events such as flood or drought must be considered.

• Leptospirosis:
• Infection in humans via contaminated water, soil, infected animal tissue or infected animal bites
• Subclinical animals can shed leptospires in urine
• Most common carriers in US: dogs, cattle, rats
• Bears successfully exploit anthropogenic resources in urban and suburban environments (garbage disposal units) bc behavioral plasticity, intelligence and omnivorous food habits

Study design: To determine if black bears w/ greater human housing density/km2 would have greater likelihood to test positive for lepto. Sampled serum from black bears around Asheville, NC + collected kidneys and bladder from roadkill bears. Tested for 5 lepto serovars [Canicola, Icterohaemorrhagia, Pomona, Hardjo, Grippotyphosa] using microscopic agglutination test (MAT) + PCR on tissues and serum

• 96 serum samples tested w/ MAT, 125 tissue and serum samples tested w/ PCR
• 9% prevalence w/ MAT vs 2% prevalence w/ PCR
• All MAT positive for L. Grippotyphosa
• None of the MAT positive samples had corresponding positive PCR
• MAT tests for specific serovars, possible that PCR positive were positive for different serovar
• Also possible that bears are incidental hosts capable of eliminating leptospira before they develop antibody titers
• MAT insensitive in first 10d of infection (bc antibody response not mounted)
• No sig influence of housing density, age or sex
• Not limited to densely populated areas
• Prevalence considered low compared to raccoons, skunks, bobcats, squirrels
• Presence of Grippotyphosa in bears may suggest risk to dogs in which this serovar is associated w/ disease

Take-away: Low prevalence of L. interrogans serovar Grippotyphosa in black bears in urban environment in NC

Question 40

A recent paper describe laparoscopic ovariectomy in an Asiatic black bear.

What are the advantages of using this procedure?

Where were the cannulae placed?

What were some of the unique aspects of this surgery?

Answer 40

Lee, S. Y., Jeong, D. H., Seok, S. H., Yang, J. J., Kong, J. Y., Park, S. J., … & Yeon, S. C. (2017).

Laparoscopic ovariectomy in the asiatic black bear (ursus thibetanus) with the use of the sonicision™ device.

Journal of Zoo and Wildlife Medicine, 48(1), 213-216.

Abstract: Laparoscopic ovariectomy was performed in two Asiatic black bears (Ursus thibetanus). Bears were placed in a 20° Trendelenburg position on a surgical table. A three-portal technique was used. A camera port was established 10 cm caudal to the umbilicus with a 5-mm cannula. Two instrument ports were made 1 cm caudal to the umbilicus with a 5-mm cannula and 8 cm caudal to the camera port with a 12-mm cannula, respectively. The suspensory ligament, ovarian vasculature, and uterine horn tip were progressively dissected following coagulation with the Sonicision™ cordless ultrasonic dissection device. The resected ovary was exteriorized through the 12-mm instrument portal site but enlarged to a 2-cm incision length. The abdominal musculature, subcutaneous tissue, and skin of the portal sites were closed separately. Total surgical time was 113 min (Bear A) and 49 min (Bear B), and no postoperative complications were encountered. This is the first report of laparoscopic ovariectomy in the Asiatic black bear.

Key Points

• Advantages of laparoscopic surgeries for wildlife:
  
  • Minimal tissue incision, pain reduction, shortened recovery times.
• Other reports have used 3 portal techniques with cannulae in a triangle position in bears.
  
  • In this study, used a straight midline position for cannulae.
    
    • Efficient to access and manipulate bilateral ovaries without instrument conflicts.
• Factors that influenced surgery:
  
  • Prominent fat depositions in ovarian pedicle.
  • Removal of the ovaries required an additional portal site incision.
    
    • To save time, both ovaries were removed from the abdominal cavity simultaneously with the use of an OHE hook or transabdominal suspension suture securing formerly resected ovary to the body wall.
  • Difficult to ID ovarian vasculature.

Take Home: Laparoscopic ovariectomy with the use of a Sonicision device was a safe and efficient method of sterilization in Asiatic black bears.

Question 41

A recent paper describe streptococcal myocarditis in a brown bear.

What were the gross and histologic lesions in this animal?

What heart diseases have been reported in bears?

What strep organism was isolated?

Answer 41

Ipek, V., Gocmen, H., & Cangul, I. T. (2017). Isolation of streptococci from a fatal case of myocarditis in a captive brown bear (ursus arctos). Journal of Zoo and Wildlife Medicine, 48(1), 269-271.

Abstract: A 10-yr-old, male brown bear (Ursus arctos) from Bursa Zoo in Turkey died without any apparent signs. Severe purulent pericarditis and myocarditis with mild ascites, lung edema, and moderate liver congestion were observed during necropsy. Microscopically, there were severe neutrophilic infiltrations in the myocardium and thoracic lymph nodes. A member of the Streptococcus bovis-Streptococcus equinus complex (SBSEC) was isolated and identified phenotypically.

• Streptococcus sp.
  
  • Gram-positive bacteria
  • Commonly found in skin and upper GI tract
• Streptococci have been isolated from oral flora and from a case of aspiration pneumonia as a secondary contaminant in American black bears
• Case: 10-yr-old male brown bear presented for necropsy
  
  • No clinical signs prior to death
  • Findings:
    
    • Gross: Serosanguinous pleural effusion, fibrinopurulent exudate in pericardium with bloody fibrinopurulent material in pericardial sac, epicardial ecchymoses and yellow nodules in the myocardium, mediastinal lymphadenopathy, pulmonary edema, hepatic congestion and peritoneal effusion
    • Cytology – coccoid bacteria and degenerate neutrophils
    • Histo: infiltration of neutrophils and mononuclear inflammatory cells, mostly perivascular, in heart (myocardium, epicardium and endocardium), necrosis, fibrous tissue and some coccoid bacteria, centrilobular hepatocellular degeneration and necrosis, pulmonary edema and congestion, neutrophil infiltrations in thoracic lymph nodes
    • Culture - Streptococcus bovis type II/ 4 (member of Streptococcus bovis-Streptococcus equinus complex)

Heart disease in bears

• Previously reported cases:
  
  • Valvular endocarditis caused by Staphylococcus aureus in black bear
  • Hemorrhagic myocarditis caused by Clostridium sordellii in brown bear

Streptococcus bovis type II

• Molecular diagnostic methods often needed to accurately identify this organism

Question 42

A recent study evaluated the prevalence fo babesia, ehrlichia, and ticks in American black bears in Oklahoma.

What tick was found most commonly? How prevalent was it?

How prevalent was Ehrlichia?

How prevalent was Babeisa?

What tick-borne diseases have been reported in bears previously?

Answer 42

Skinner, D., Mitcham, J. R., Starkey, L. A., Noden, B. H., Fairbanks, W. S., & Little, S. E. (2017).

Prevalence of Babesia spp., Ehrlichia spp., and tick infestations in Oklahoma black bears (Ursus americanus).

Journal of wildlife diseases, 53(4), 781-787.

Abstract: American black bears (Ursus americanus) are commonly infested with ticks throughout their range, but there are few surveys for tick-borne disease agents in bears. To characterize tick infestations and determine the prevalence of current infection with Babesia spp. and past or current infection with Ehrlichia spp. in newly re-established populations of black bears in east central and southeastern Oklahoma, US, we identified adult (n=1,048) and immature (n=107) ticks recovered from bears (n¼62). We evaluated serum and whole blood samples from a subset (n¼49) for antibodies reactive to, and characteristic DNA fragments of, Ehrlichia spp., as well as characteristic DNA fragments of Babesia spp. Amblyomma americanum, the most common tick identified, was found on a majority (56/62; 90%) of bears and accounted for 697/1,048 (66.5%) of all ticks recovered. Other ticks included Dermacentor variabilis (338/1,048; 32.3%) from 36 bears, Amblyomma maculatum (9/1,048; 0.9%) from three bears, and Ixodes scapularis (4/1,048; 0.4%) from three bears. Antibodies reactive to Ehrlichia spp. were detected in every bear tested (49/49; 100%); maximum inverse titers to Ehrlichia chaffeensis ranged from 64–4,096 (geometric mean titer 1,525). However, PCR failed to identify active infection with E. chaffeensis, Ehrlichia ewingii, or an Ehrlichia ruminantium-like agent. Infection with Babesia spp. was detected by PCR in 3/49 (6%) bears. Together these data confirm that tick infestations and infection with tick-borne disease agents are common in bears in the southern US. The significance of these infestations and infections to the health of bears, if any, and the identity of the Ehrlichia spp. responsible for the antibody reactivity seen, warrant further evaluation.

• Black bears in northeastern & western US – Anaplasma, Babesia, Borrelia, and Rickettsia detected
• Ticks on every bear – except on those denning in winter

Take Home: Amblyomma americanum most common tick, Ehrlichia chaffeensis very common

Question 43

A recent study describe aortic aneurysms in bile-farmed bears.

What species are commonly farmed for bile?

What is that process like? What are some common diseases associated with it?

How did these bears present?

What were the lesions on necropsy?

What were the suspected causes?

Answer 43

Bando, M. K. H., Nelson, O. L., Webster, N., Ramsay, J. D., Bacon, H. J., & Sellon, R. (2018).

Aortic aneurysm, dissection, and rupture in six bile-farmed bears.

Journal of Zoo and Wildlife Medicine, 49(3), 738-747.

Abstract: Across China and Southeast Asia, over 17,000 bears are currently farmed for bile, predominantly for traditional Chinese medicines. Bears on farms in China are cage confined and undergo repeated daily bile extraction facilitated by surgically implanted catheters or gallbladder fistulas. Numerous health problems have been reported in bile-farmed bears including peritonitis, abdominal hernias, and extraction site abscessation. Between 2009 and 2014, five Asiatic black bears (Ursus thibetanus) and one Asiatic black/Eurasian brown bear (Ursus arctos arctos) hybrid, rescued from the bear bile industry in China, died from ruptured and/or dissecting aortic aneurysm. Medical records were reviewed and two bears exhibited no clinical signs prior to death. In four bears, clinical findings varied and included increased stereotypic behavior prior to death, epistaxis, retinal lesions, dysphagia, weight loss, and acute onset of hyporexia. On postmortem examination, hemopericardium with dissection and/or rupture of the ascending aorta and left ventricular wall hypertrophy were present in all cases. No evidence of infectious disease, connective tissue disorders, or congenital cardiac disease was identified. Based on these observations screening thoracic radiography was performed on all bears at the rescue center and aortic dilation was identified in 73 of 134 (54.5 % ) bile-extracted bears. To the authors’ knowledge, aortic aneurysm, rupture, and/or dissection have not been previously reported in any bear species and the high prevalence in this population of bears suggests an association with bile-farming practices. Future studies are needed to investigate the etiopathogenesis of this condition to aid in early diagnosis and improved management of bears being rescued from bile farms across Asia.

• Asiatic black bear aka moon bear - predominant species farmed for bile
  
  • Eurasian brown bears and Malayan sun bears also farmed for bile
• Bile farmed bears:
  
  • Repeated daily bile extraction facilitated through surgically implanted transabdominal gallbladder catheter or transabdominal gallbladder fistula
  • Common disease: peritonitis, abdominal hernias, abscessation around extraction site
  • Common causes of death: hepatic neoplasia, deteriorating mobility including spinal paralysis and paresis, cardiovascular disease (mostly aortic aneurysm rupture or CHF)
• Case series of rescued bile farm bears that acutely died from aortic aneurysm rupture and/or dissection
  
  • High prevalence of aortic dilation detected by radiographic screening of bears rescued from bile farms
  • Nonspecific and overall minimal clinical signs prior to death of affected bears
  • Systemic hypertension suspected to be the underlying cause
    
    • Predominant cause in humans, gorillas
    • Concurrent left ventricular wall hypertrophy present at necropsy in all bears -suspicious for systemic hypertension as cause of aortic aneurysm
    • Some bears also had documented hypertension under anesthesia
  • Cause of hypertension unknown – r/o renal disease, chronic stress, etc
  • Condition suspected to be related to bile farming

Question 44

A recent study described the serotypes and resistance of Escherichia coli in wild Giant Pandas.

What were the most prevalent serogroups?

Antimicrobial resistance was highest for which antibiotics?

What is the leading cause of decline in wild giant pandas? What pathogens are associated with it?

Answer 44

Chen, D., Zou, W., Xie, S., Kong, L., Chen, Y., Zhang, X., … & Yang, X. (2018).

Serotype and antimicrobial resistance of escherichia coli isolated from feces of wild giant pandas (ailuropoda melanoleuca) in sichuan province, china.

Journal of wildlife diseases, 54(4), 691-699.

Abstract: Escherichia coli is a major pathogen leading to systemic and enteric illnesses in wild giant pandas (Ailuropoda melanoleuca). To investigate the characteristics and distribution of E. coli in wild giant pandas across four different nature reserves in Sichuan, Republic of China, we researched serotypes, phylogenetic groups, antimicrobial resistance, and resistance genes of E. coli not previously reported for wild giant pandas. A total of 82 E. coli isolates were identified from 40 fecal samples in August 2016 to May 2017. The most-prevalent serogroups were O15 (4%, 3/82), O28 (2%, 2/82), and O44 (2%, 2/82). Antimicrobial resistance was highest for streptomycin (61%, 50/82) followed by amikacin (30%, 25/82). Among the four nature reserves, the proportion of streptomycin (86%, 12/14) and amikacin (57%, 8/14) was highest in Liziping. The frequencies of resistant genes aph(30)-IIa, ant(300)-Ia, aac(3)-IIa, aadA1, and StrB were 28, 23, 5, 21, and 32%, respectively, while none of the strains had the tetracycline gene. In Qianfoshan, the phylogenetic group B2 was the most common, comprising the highest percentage of isolates compared with the other seven phylogenetic groups. Furthermore, many variables such as phylogenetic groups, antimicrobial susceptibility, and resistance genes differed significantly (P,0.05) among the four nature reserves. In facilitating the safe discharge of captive giant pandas into the wild, as well as to support existing wild populations, the data from this research will prove invaluable to scientists and ecologists in their endeavors.

• Intestinal disease is the leading cause of decline in wild giant pandas – E. coli, Klebsiella, Campylobacter, Pseudomonas, Yersinia, Clostridium
• Some E. coli strains have virulence factors – enteropathogenic (EPEC), enterohemorrhagic (shiga-toxin, ETEC), enteroinvasice (EIEC)
• 18% of isolates were ETEC, EIEC, or EPEC serotypes
• 66% of isolates had resistance to at least one antimicrobial, 40% were resistant to two or more on susceptibility
  
  • 56% had at least one resistance gene, 37% had at least 2
• Wild pandas have considerably lower resistance rates than managed counterparts
  
  • Managed panda isolates tend to be resistant to tetracycline and gentamycin
  • Wild panda isolates tend to be resistant to streptomycin and amikacin

Take Home: E. coli is a big problem for wild pandas, many of the strains are multi-drug resistant

Question 45

A recent study evaluated the use of serology to monitor sarcoptic mange prevalence in American black bears.

What test was validated in this study?

How prevalent was sarcoptes in this Pennsylvania population?

What other mites commonly affect bears?

Answer 45

Journal of Wildlife Diseases, 56(2), 2020, pp. 350–358

SEROLOGY AS A TOOL TO INVESTIGATE SARCOPTIC MANGE IN AMERICAN BLACK BEARS (URSUS AMERICANUS)

Kevin D. Niedringhaus, Justin D. Brown, Mark Ternent, Sarah K. Peltier, Peach Van Wick, and Michael J. Yabsley– Reviewed by MM

Abstract: Black bears (Ursus americanus) have historically been considered an uncommon host for sarcoptic mange. However, over the last 25 yr, sarcoptic mange has been increasingly reported in black bears in the northeastern US. Syndromic monitoring is the most common surveillance approach for mange in bears, but tools to monitor exposure to Sarcoptes scabiei in bear populations have not been thoroughly evaluated under field conditions. In this study, we validated a commercially available enzyme-linked immunosorbent assay (ELISA), designed to detect antibodies against S. scabiei in dogs, for use in black bears with a sensitivity and specificity of 95.6% and 96.6%, respectively. To further examine the performance of this assay, serial serum samples from seven black bears with confirmed sarcoptic mange were collected posttreatment to determine the persistence of detectable antibody response with the ELISA. Antibodies in black bears waned to below the limit of detection between 4 and 14 wk, suggesting that serology studies might underestimate the number of exposed black bears after antibodies have waned. State-wide serosurveys in Pennsylvania from hunter-harvested black bears in 2017 and 2018 showed a significant difference in seroprevalence between regions with high occurrence of mange (mean seroprevalence 6.7%, range of 6.6–6.8%) and low occurrence of mange (no seropositive black bears were detected). Within Pennsylvania, these data indicate that the geographic distribution of exposure to S. scabiei, based on serologic testing, generally reflects the distribution of overt disease, as determined by syndromic surveillance. Collectively, these results indicate the evaluated ELISA is an effective tool for monitoring S. scabiei exposure in bear populations and provides the framework for additional studies regarding sarcoptic mange epidemiology in black bears.

• Introductions of Sarcoptes scabiei into susceptible populations has resulted in swift widespread morbidity and mortality
• Current methods for investigating the prevalence of disease rely on scrapes and individual skin samples
• Developed a serology test – mean seroprevalence was 6.7% - consistent over the years 2017 & 2018
• Antibodies from clinically normal animals might be from exposure without development of clinical disease or recovered clinical mange cases as seen in Iberian Ibex and chamois
• Other black bear mites
  
  • Demodex ursi
  • Ursicoptes americanus
  • Cross reactivity with this test unknown

Take home: Serology can now be done on black bears to evaluate Sarcoptes prevalence on a population level

Question 46

A recent study evaluated assays to detect the causative agents of mange in free-ranging black bears.

What are the three mite species associated with mange in American black bears?

What was the cold standard for determining mite infestation?

Which mites were identified?

What histologic lesions were seen in these bears?

How prevalenct was exposure to these mites in these bears?

Answer 46

Peltier, S. K., Brown, J. D., Ternent, M. A., Fenton, H., Niedringhaus, K. D., & Yabsley, M. J. (2018). Assays for detection and identification of the causative agent of mange in free-ranging black bears (Ursus americanus). Journal of wildlife diseases, 54(3), 471-479.

Three mite species (Demodex ursi, Ursicoptes americanus, and Sarcoptes scabiei) have been associated with mange in black bears (Ursus americanus). Since the early 1990s, the number and geographic distribution of mange cases in black bears in Pennsylvania, US has increased; however, the causative mites have yet to be completely defined. We evaluated several diagnostic approaches for detection and identification of mites in 72 black bears with severe lesions consistent with mange. Sarcoptes scabiei was morphologically identified in skin scrapes from 66 of the bears; no mites were identified in the remaining six. Histopathologic lesions consistent with sarcoptic mange were observed in 39 of 40 bear skin samples examined, and intralesional mites were observed in samples from 38 of these bears. Samples were collected from a subset of the 72 bears for PCR testing targeting both the internal transcribed spacer (ITS)-2 region and cytochrome c oxidase I (cox1) gene including 69 skin scrapes (ITS-2 only), 56 skin biopsies (ITS-2 and cox1), and 36 fecal samples (ITS-2 and cox1). Skin scrapes were a more sensitive sample for PCR detection than either skin biopsies or fecal samples, and the ITS-2 primers proved more sensitive than cox1. Using a commercial indirect enzyme-linked immunosorbent assay, antibodies to S. scabiei were detected in 45/49 (92%) black bears with confirmed mange and 0/62 (0%) cubs with no gross lesions suggestive of mange and which were born to seronegative sows. Sarcoptes scabiei was the predominant mite associated with mange in black bears in Pennsylvania. Diagnostically, cytologic examination of skin scrapes was the most effective approach for diagnosing active mite infestations in black bears. The evaluated serologic assay accurately detected antibodies to S. scabiei in most bears with confirmed S. scabiei infestations. Additional research is needed to determine the usefulness of this approach for larger scale surveys and for asymptomatic bears.

• Gold standard for dx active mite infestations – cytologic examination of skin scrapes from affected skin for mite ID.
  
  • Cytology may be ineffective with mild or no lesions, mite burdens may be low, locations to scrape may be inapparent.
  • Molecular diagnostics, variable results.
  • Serology can ID individuals with previous exposure or chronic infestations without overt lesions.
  • Histology can detect presence of intralesional mites and characterize lesions assoc with mange. Mite species often cannot be determined.
• Materials and Methods
  
  • Collected samples from 72 black bears from PA with gross lesions.
    
    • Skin scrapes, biopsies. Looked at cytology, used skin scrape/biopsy/fecal materials for PCR, biopsies for histo, serology from serum samples.
• Results & Discussion
  
  • S. scabiei only mite species found.
  • PCR of skin biopsies lower vs skin scrape material.
  • Histo – Mites found in 95% with severe mange, lesions consisted of moderate to severe acanthosis and neutrophilic epidermitis with large serocellula rcrusts, marked parakeratotic hyperkeratosis, seconday bacterial conlonization in most, some yeast.
  • Serum samples – 92% positive serology in confirmed cases.

Takeaway: Sarcoptes scabiei is the primary cause of mange in black bears in PA. Cytology (skin scrape) effective dx tool for bears with mange. PCR can also be used, less sensitive.

Question 47

A recent study evaluated bear cerebrospinal fluid.

Where was the CSF collected from?

How did it compare to domestic species?

Answer 47

Wright, H. L., Chen, A. V., & Jansen, H. T. (2019).

COMPOSITION OF CEREBROSPINAL FLUID IN CLINICALLY NORMAL GRIZZLY BEARS (URSUS ARCTOS HORRIBILIS).

Journal of Zoo and Wildlife Medicine, 50(3), 739-741.

Abstract: Five cerebrospinal fluid (CSF) samples were collected from four clinically normal grizzly bears from the Washington State University Bear Research, Education, and Conservation Center. CSF samples were collected from the cerebellomedullary cisternal space. Samples were immediately processed and analyzed for microprotein content, red blood cells, white blood cells (WBCs), and differential cell count. Microprotein concentration (range 4.2–14.6 mg/dl; median, less than 6 mg/dl), total WBC count (range 0–2 cells/µl; median 2 cells/µl), and differential WBCs (predominance mononuclear cells) of the five CSF samples were comparable to previously published CSF analyses from clinically normal felines and canines. Providing documentation of CSF composition for clinically normal grizzly bears is important for neurologic disease diagnosis and treatment.

• Slightly lower microprotein and similar WBC counts vs previously reported values for normal adult equine, bovine, and camelid spp.
• Canine WBC cells/micro L < 5-6; all bears here < 3.

Question 48

A recent study established the reference values for hematology, biochemistry, and urinalysis in the Giant Panda.

What is the predominant leukocyte of pandas?

What enzyme was higher than other bears?

What was their urine like?

Answer 48

Burrell, C., Zhang, H., Li, D., Wang, C., Li, C., & Aitken-Palmer, C. (2017).

Hematology, serum biochemistry, and urinalysis values in the adult giant panda (Ailuropoda melanoleuca).

Journal of Zoo and Wildlife Medicine, 48(4), 1072-1076.

Abstract: The giant panda (Ailuropoda melanoleuca) is a high-profile threatened species with individuals in captivity worldwide. As a result of advances in captive animal management and veterinary medicine, the ex situ giant panda population is aging, and improved understanding of age-related changes is necessary. Urine and blood samples were collected in April and July 2015 and analyzed for complete blood count, serum biochemistry, and biochemical and microscopic urine analysis for all individuals sampled (n = 7, 7–16 yr of age) from giant panda housed at the China Research and Conservation Centre for the Giant Panda in Bifengxia, Sichuan Province, China. Hematology and serum biochemistry values were similar to those previously reported for giant panda aged 2–20 yr and to Species360 (formerly International Species Information System) values. Urine was overall dilute (urine specific gravity range: 1.001–1.021), acellular, and acidic (pH range: 6–7). This is the first report of hematologic and serum biochemistry, with associated urinalysis values, in the giant panda aged 7–16 yr.

• No previous reported urinalysis results for pandas
• This study aim was to report CBC/CHEM/UA value for older pandas to help develop age specific reference ranges
• Blood:
  
  • Pandas primarily granulocytic. 60% grans to 20% lymphs.
  • Amylase concentrations were considerably higher than for other bear species
• Urine
  
  • Hyposthenuric compared to domestic dog/cat ranges (1.001-1.021)
  • Aciduria (pH 6-7)
  • Ketones in 5 animals – unexpected. Cause unknown.

Take home point: The dilute, acellular, acidic urine found in these seven giant pandas was unexpected. Ketones may be found in healthy pandas. Unknown cause.

Question 49

A recent study established the pharmacokinetics of fluralaner in American black bears.

What is the mechanism of fluralaner?

What is the life cycle of sarcoptes?

What dose of fluralaner was used? What was teh half-life? What was the estimated withdrawal time?

Answer 49

Journal of Zoo and Wildlife Medicine 51(3): 691–695, 2020

PHARMACOKINETICS OF A SINGLE DOSE OF FLURALANER ADMINISTERED ORALLY TO AMERICAN BLACK BEARS (URSUS AMERICANUS)

Peach Van Wick, DVM, MS, Mark G. Papich, DVM, MS, Brie Hashem, MS, and Ernesto DominguezVillegas, DVM, Dipl ACVPM

Abstract: Sarcoptic mange continues to impact free-ranging mammal populations, including the American black bear (Ursus americanus). Administration of a single oral dose of fluralaner may be a viable treatment option for captive and free-ranging black bears affected by mange. This novel ectoparasitic in the isoxazoline class acts as an inhibitor of c-aminobutyric acid (GABA)-gated chloride channels and L-glutamate–gated chloride channels (GluCls) and is commercially available in the United States as a flea and tick preventative medication for domestic dogs and cats. Pharmacokinetic parameters of fluralaner were evaluated in clinically healthy American black bear cubs (n =10) administered a single oral dose of fluralaner at a targeted minimum dose of 25 mg/kg. Blood was collected at 24 hr and 7, 14, 21, 28, 35, 42, 49, 56, 63, and 70 days, and harvested plasma was analyzed for drug concentration using high-performance liquid chromatography. The average half-life (Ke t1/2) was determined to be 4.9 days, which is shorter than that published in domestic dogs. It was estimated that the average drug withdrawal time is approximately 64–72 days in this species.

Key Points

• Scabies documented in over 100 mammalian species including American black bears
• Life cycle of the mite takes 2 weeks for eggs to become adults
• Ivermectin is only effective on adult stages
• Fluralaner (bravecto) is administered every 12 weeks – may be sufficient for one-time dosing in bears but withdrawal information is needed since they are game species
• Cubs from WCV were given 22-46 mg/kg (mean 31 mg/kg)
• Cmax higher than in dogs, but half-life shorter than in dogs

Take Home: Fluralaner may be useful for single dose treatment in affected black bears – withdrawal time is about 2 months

References:

• Van Wick M, Hashem B. Treatment of sarcoptic mange in an American black bear (Ursus americanus) with a single oral dose of fluralaner. J Wildl Dis. 2019; 55(1):250–253

Question 50

A recent study described the use of fluoxetine to address stereotypies in Asiatic black bears.

What dose did they use?

Was it sufficient to stop the stereotypies?

Answer 50

Jeong, D. H., Yang, J. J., & Yeon, S. C. (2019). Fluoxetine therapy to decrease stereotypic behavior in the asiatic black bear (ursus thibetanus). Journal of Zoo and Wildlife Medicine, 50(3), 718-722.

Abstract: The present study evaluated the effects of fluoxetine on decreasing stereotypic behaviors in Asiatic black bears (ABB). Four captive ABB exhibiting stereotypic behaviors were administered fluoxetine (0.25–1 mg/ kg orally every 24 hr) for 91 days. The animals were monitored twice weekly for 213 days (April to October) using a scan sampling method (preadministration, 30 day; administration, 91 days; postadministration, 92 days). Five blood samples were collected from the jugular vein of each bear for serum chemistry analysis (one during preadministration; two each during administration and postadministration periods). Fluoxetine was safe and effective in decreasing stereotypies, but it may be difficult to decrease long-established stereotypies in ABB using fluoxetine alone. To decrease stereotypies in ABB effectively, it is necessary to identify underlying problems that contribute to stereotypic behavior and apply comprehensive interventions that can include fluoxetine treatment.

• Ursids have highest incidence of stereotypies in bears. Pharmacological and enrichment approaches produce mixed results.
• Bears non-releasable (or re-captured due to human interactions)
• Stereotypic behaviors noted after 20-42 months in captivity.
• Ethogram created. Behaviors included pacing, two-feet stepping, stepping backward after pacing, forepaw self-sucking, repetitive head rearing
• Fluoxetine given at 0.62mg/kg for first 31 days, 1mg/kg for 30d then weaned down over 30 days.
• Bloodwork fairly unremarkable aside from amylase increase post-administration period
• Well-established stereotypy could negative affect efforts to decrease that behavior
  
  • Separation anxiety and duration of maternal care (shorter-🡪 more stereotypies) possible contributors to stress and later anxiety
• Multifactorial approach including behavior modification, enrichment programs, improving animal’s environment combined with medications recommended
• Longer medication period (180d) may be more successful

TAKE HOME: Multifactorial approach recommended with longer treatment duration (180d) recommended to attempt to treat stereotypies in bears

Question 51

A recent study described the use of oclacitinib to manage Andean bear alopecia syndrome.

How common is alopecia syndrome in Andean bears? What is the typical signalment?

How does the disease progress?

What is the mechanism of oclacitinib?

What are some of the advserse reactions associated with its use?

How effective was this treatment?

Answer 51

Journal of Zoo and Wildlife Medicine 48(3): 818–828, 2017

TREATMENT SUCCESS IN THREE ANDEAN BEARS (TREMARCTOS ORNATUS) WITH ALOPECIA SYNDROME USING OCLACITINIB MALEATE (APOQUEL®)

Gabby J. Drake, B.V.Sc., M.Sc., Tim Nuttall, B.V.Sc., Ph.D., Javier López, Ldo. Vet., M.Sc., William Magnone, D.V.M., Antoine Leclerc, D.V.M., Dipl. E.C.Z.M. (Z.H.M.), Romain Potier, D.V.M., Alexis Lécu, D.V.M., Maëlle Guézénec, D.V.M., Lydia Kolter, Dipl. Biol., Dr. Rer. Nat., Amélie Nicolau, D.V.M., Karin Lemberger, D.V.M., Dipl. A.C.V.P., Didier Pin, D.V.M., Dipl. E.C.V.D., and Sallie B. Cosgrove, M.S., D.V.M.

Abstract: Andean bear (Tremarctos ornatus) alopecia syndrome (ABAS) commonly affects captive bears, particularly sexually mature females. ABAS is characterized by bilaterally symmetrical predominantly flank alopecia with or without profound pruritus and secondary bacterial and Malassezia infections. There is no effective treatment and severely affected bears have been euthanized. This paper describes the successful management of ABAS in three female Andean bears. Skin biopsies and cytology revealed a mixed dermal inflammatory infiltrate, alopecia, hyperkeratosis, and Malassezia dermatitis. Allergen specific serology was positive for environmental allergens in one case. Hematology, serum biochemistry, and thyroid and adrenal function were normal in all cases. There was no consistent response to novel diet trials, antifungals, antihistamines, allergen specific immunotherapy, or topical antimicrobials. There was a partial response to ciclosporin (Atopicat cat, Novartis Animal Health; 5 mg/kg po, sid) in one case and oral glucocorticoids in all cases (dexamethasone sodium phosphate, [Colvasone 0.2%, Norbrook], 0.15 mg/kg po, sid or prednisolone [Deltacortene, Bruno Farmaceutici, and Megasolone 20, Coophavet], 0.3–1.2 mg/kg po, sid), but treatment was withdrawn following adverse effects. Treatment with oclacitinib maleate (Apoquelt, Zoetis; 0.46–0.5 mg/kg po, bid) resulted in rapid and complete resolution of the pruritus with subsequent improvement in demeanor and fur regrowth. After 5 mo, the bears were almost fully furred and off all other medication. Treatment was tapered to the lowest dose that prevented relapse of the pruritus (0.23–0.4 mg/kg po, sid). No adverse effects have been noted. ABAS is usually an intractable condition, and, to our knowledge, oclacitinib is the first treatment shown to result in sustained clinical improvement. Further studies on the etiology of ABAS, and on efficacy and long-term safety of oclacitinib are needed.

Key Points:

• Up to 27% of female Andean bears in captivity are predisposed to this alopecic syndrome
  
  • Strong bias for females over 3 years old
• Disease progression
  
  • Alopecia leading to secondary infections, pruritus, and lichenification
  • Histo – diffuse perivascular lymphocyte and eosinophil inflammation with follicular atropy and occasionally multinucleated giant cells, acanthosis, orthokeratosis, and secondary infection
  • Etiology remains unclear but appears to be atopy like but may have some neuroendocrine mechanism not understood
• Oclacitinib
  
  • Janus kinase (JAK-1) inhibitor
  • Inhibits transduction of IL 2, 4, 6, 13, and 31 with 31 being the big one for pruritus
  • Adverse reactions – weight gain, behavior changes, anemia, leukopenia, infection, hepatopathy, neoplasia
• Case workup
  
  • Begin with scrapes and impressions – eliminate parasites and infection
  • Strong seasonality to cases – consider allergy testing – may have endocrine component as well

Take Home: Oclacitinib is a potential treatment for Andean bear alopecic syndrome

Question 52

A recent study described a novel neoplasia in an Eurasian brown bear.

What was the mass? Where had it metastasized to?

Answer 52

Balseiro, A., Royo, L. J., Gayo, E., & García Marín, J. F. (2020). Cholangiocarcinoma in a free-ranging Eurasian brown bear (Ursus arctos arctos) from Northern Spain. Journal of wildlife diseases, 56(1), 251-254.

ABSTRACT: A hepatic cholangiocarcinoma with metastases in the gallbladder, left elbow joint, adrenal glands, and lungs was observed in a female 21-yr-old free-ranging Eurasian brown bear (Ursus arctos arctos) found in the Principality of Asturias (northern Spain). Gross and histopathologic findings are described.

• Cholangiocarcinoma have unknown etiology and usually highly invasive growth pattern
  
  • Metastases to regional LN, lung, peritoneal cavity
• First report in free ranging bear 🡪 previously in polar bear, Himalayan brown bear, sloth bear
• Geriatric free-ranging female Eurasian brown bear in poor health and poor BCS
  
  • Ascites, hydrothorax, and hydropericardium
• Masses disrupting 60% of the hepatic parenchyma 🡪 white to yellow-brown, firm with multiple areas of necrosis
  
  • Metastasis to gallbladder, left elbow joint, adrenal glands, and lungs 🡪 retained characteristics of biliary epithelium on histo
• Bone metastasis is rare and not previously seen in bears
• Usually older animals affected

Take home: First report hepatic cholangiocarcinoma in a free ranging bear

Question 53

A recent study evaluated the endoparasites of formosan black bears.

Which was the most prevalent parasite identified?

Answer 53

Journal of Wildlife Diseases, 57(2), 2021, pp. 345–356

ENDOPARASITES OF FORMOSAN BLACK BEARS (URSUS THIBETANUS FORMOSANUS) DURING ACORN SEASON IN YUSHAN NATIONAL PARK, TAIWAN

Mei-Hsiu Hwang, Ting-Wei Chin, and Pin-Huan Yu – reviewed by MSM

Abstract: Parasite infection is one of the most important factors in wildlife conservation. However, fecal parasite profiles of threatened Asiatic black bears (Ursus thibetanus) are only sporadically reported, and the effect of parasitic diseases on the survival of the locally endangered Formosan black bear (Ursus thibetanus formosanus) in Taiwan remains undetermined. The study objective was to investigate the gastrointestinal parasite profiles of Formosan black bears in Yushan National Park, the only known high-density habitat for the species in Taiwan. Bear fecal samples were collected in the acorn season (from October to February) from January 2008 to October 2012. To avoid bias created by repeat sampling, the parasite profiles of fecal samples collected in 2010 from 46 individually identified bears (which were identified by genetic analysis) were also examined. Parasites were isolated by various methods and identified by morphologic characteristics. A total of 220 samples were analyzed and the results were compared between seasons, sexes, and individuals. The overall frequency of parasite infection was 77.3%, and it varied by species, with Baylisascaris transfuga infection being the most frequent. We suggest that one factor underlying the high frequency and high intensity of infection that we observed is the fact that the bears seasonally congregated at high density in a small area. To our knowledge, this is the first thorough study of gastrointestinal parasites in Asiatic black bears. The long-term nature of the investigation and the relatively stable frequency and intensity of infection suggest that parasitic diseases could serve as bioindicators of ecosystem health.

• Formosan black bear – subspecies of Asiatic black bear, only ursid on Taiwan – threatened by poaching, illegal trade, and habitat loss.
• In Taiwan these bears don’t hibernate but congregate seasonally to feed on acorns which may enhance parasite transmission
• Fecal evaluation identified five nematodes
  
  • Baylisascaris transfuga – 65.5%
    
    • High prevalence in Brown and black bears as well
    • No differences in sexes in these bears – unlikely American black bears where males had higher prevalence
    • Reported in all bear species – no cause of mortality has been reported
      
      • Larval migrans has been reported in moose, birds, and macaques
    • The related B. shroederi is a cause of death in wild giant pandas
  • Strongyloides spp – 11.4% - can be pathogenic to young animals
  • Hookworm – 9.6%
  • Trichostrongylus & Oesophagastomum – 3.6% - may indicate ingestion of contaminated food (macaques or wild boars)
• Protozoa – Cryptosporidium (2.7%)
• Cestode – Taenia (0.5%)
• Physlapetera & Gongylonema – 1% - ingestion of wild beetles

Take Home: Baylisascaris transfuga is the predominant endoparasite of Formosan black bears

Question 54

A recent study evaluated centrilobular hepatic necrosis in neonatal giant panda cubs.

What causes CHN?

How does neonatal panda lung development differ from other mammals?

What is the proposed pathogenesis of CHN in these cubs?

Answer 54

Journal of Zoo and Wildlife Medicine 52(3): 926–938, 2021

PERINATAL CENTRILOBULAR HEPATIC NECROSIS IN GIANT PANDAS (AILUROPODA MELANOLEUCA): A RETROSPECTIVE STUDY

John F. Roberts, DVM, Dipl ACVP, Suzan Murray, DVM, Dipl ACZM, David M. Love, DVM, Margaret A. Hanson, DVM, Dipl ACVP, Sarah L. Hale, DVM, Dipl ACVP, Timothy F. Walsh, DVM, Dipl ACVP, Desheng Li, BS, and Kali A. Holder, DVM, Dipl ACVP – Reviewed by MSM

Abstract: Between 1983 and 2012, six giant panda cubs (Ailuropoda melanoleuca) born at a zoological institution were stillborn or died between the ages of 3 and 200 h. Two of the six cubs had panhepatic centrilobularhepatic necrosis (CHN), granulocytic extramedullary hematopoiesis (GEM), positive liver culture for Staphylococcus species, and terminal liver failure. Another low-weight cub was administered oxygen therapy immediately after birth and developed hyaline membranes in air spaces and hepatic necrosis restricted to the hilar region. A retrospective analysis of liver and lung lesions, pulmonary microanatomy, blood–gas barrier ultrastructure, and hepatic myofibroblast proliferation was conducted on the six cubs. Neonates with CHN had concurrent severe periportal GEM accompanied by severe myofibroblast proliferation. The pulmonary blood–gas barrier was markedly increased in one cub with CHN. Developmentally, the lungs of all but one cub were at the late saccular stage, and the lowest-weight cub was in early saccular stage, consistent with immaturity, and had pneumonia comparable to neonatal respiratory distress syndrome (RDS). Stage of lung development was eliminated as the primary factor leading to CHN. The pathogenesis of CHN in these neonates is proposed to be transformation of hepatic stellate cells to myofibroblasts initiating blockage and microvascular constriction of hepatic sinusoids, resulting in insufficient perfusion and cellular hypoxia of hepatocytes surrounding central veins in acinar zone 3.

Key Points:

• Diagnoses of these cubs made at necropsy include prenatal pneumonia, fetal membrane rupture, septicemia, centrilobular hepatic necrosis with concurrent granulocytic extramedullary hematopoiesis
• CHN – affects acinar zone 3, nearest the central vein/farthest from the arteries – attributed to ischemia, drug-induced injury, venous outflow impairment or perfusion/reperfusion injury
  
  • Causes – anemia in ruminants due to Haemonchus, in human neonates includes pulmonary immaturity, hypoventilation, ventilation perfusion mismatch, pulmonary edema, cardiac insufficiency, septicemia
• Fetal pulmonary development
  
  • Humans – alveolar stage, mice – saccular stage, marsupials canicular stage (require percutaneous oxygen exchange)
  • Surfactant production is also necessary for adequate ventilation
  • Pulmonary structural immaturity is an accepted cause of perinatal hypoxia in neonatal dogs that drives EMH
• Sepsis induced hypoxia also drives EMH and when it is shifted to myelocytic lineages it is termed GEM
• This paper went back through the post-mortem reports
  
  • Perinatally, giant panda cub lungs are at the saccular stage and the blood-gas barrier is on average 34% thicker than in giant panda adults
  • One individual was 2.5x thicker than adults (this individual also had the lungs thicken with survival time)
  • One cub had pulmonary prematurity with insufficient surfactant resulting in respiratory distress syndrome
  • Two cubs had evidence of chorioamniotis resulting in sepsis with Staphylococcus species – the toxins of which can further exacerbate EMH
  • One cub had a PDA and heart issues likely lead to its poor oxygenation
  • The level of EMH in healthy panda cubs is unknown

Take Home: Sepsis or other inflammatory conditions, are likely inciting the EMH that is responsible for the CHN in giant panda cubs. Any panda cub with difficulty breathing shortly after birth needs intensive care and oxygenation.

References: None in reading list.

Question 55

A recent study described Sarcocystis in American black bears and grizzly bears.

What is the general lifecycle of Sarcocystis?

Bears are the known intermediate hosts of what two Sarcocystis species.

What Sarcocystis are they the aberrant host of? What lesions result from infection?

How prevalent was this disease?

What age groups were most affected?

Answer 55

Investigation of Sarcocystis spp. Infection In Free-Ranging American Black Bears (Ursus americanus) and Grizzly Bears (Ursus arctos horribilis) In British Columbia, Canada.

Lee LK, McGregor GF, Haman KH, Raverty S, Grigg ME, Shapiro K, Schwantje H, Schofer D, Lee MJ, Himsworth CG, Byers KA.

JWD 2021;57(4):856-864.

Sarcocystis spp. are protozoan parasites that cause a spectrum of lesions in various hosts. Hepatic sarcocystosis and encephalitis have been described in captive American black bears (Ursus americanus) and polar bears (Ursus maritimus), and in a free-ranging grizzly bear (Ursus arctos horribilis), but have not previously been reported in free-ranging American black bears. This study aimed to characterize the presence and lesions associated with Sarcocystis spp. in free-ranging bears in British Columbia, Canada from samples submitted to the provincial diagnostic laboratory. From 2007 to 2019, 102 free-ranging American black bear and grizzly bear tissues were examined postmortem for sarcocystosis using histopathology and follow-up molecular diagnostics. Sarcocystosis was confirmed in 41 (40%) free-ranging bears including 39 American black bears and two grizzly bears. Microscopic lesions included multifocal necrotizing hepatitis, nonsuppurative encephalitis, and/or intramuscular sarcocysts with or without associated inflammation. Sarcocystosis was considered the cause of death in eight (20%) of these bears, exclusively in cubs of the year (<1 yr old). Sarcocystis canis was identified in 22/32 (69%) cases where molecular characterization was performed and was the etiologic agent associated with bears that died of sarcocystosis. Confirmed cases were distributed widely across British Columbia. While there was an alternate proximate cause of death in the other confirmed bears, sarcocystosis may have contributed. Age was a significant risk factor, with yearlings presenting more often with fulminant lesions; however, there was a sampling bias toward juvenile bear submissions due to size and ease of transport. Further research is needed to understand the disease epidemiology and significance to population health.

Background

• Sarcocystis - Apicomplexan
  
  • Intermediate host (herbivore/omnivore) - asexual reproduction
    
    • Lesions: myositis, encephalitis, hepatitis, mortality
  • Definitive host (consumes intermediate host) - sexual reproudction, shedding sporocysts and oocysts in feces
    
    • *Dogs can be clinically affected so definitive host of S. canis may not be known
• Bears - known intermediate host of Sarcocystis arctosi (brown bear) and S. ursusi (black bear)
  
  • Aberrant hosts of S. canis - fatal hepatic sarcocystosis +/- encephalitis in captive and free-ranging bears

Key Points

• Lesions: necrotizing hepatitis, multifocal nonsuppurative encephalitis without parasites, nonsuppurative myositis, and intramuscular sarcocysts with no inflammation.
  
  • Affected: tongue, diaphragm, appendicular muscles (myositis most severe in tongue)
  • No bears had both intrahepatic schizonts and intramuscular sarcocysts (two different stages of disease)
• Annual prevalence avg 44%, yearlings higher odds compared to adults, only a cause of death in cub-of-the-years
  
  • S. canis alone or co-infection with T gondii or Cystoisospora-like sp.
    
    • 2 bears had unique sp. Most closely associated with S. felis
  • No association with sex, body condition, or species of bear

Conclusions

• Free-ranging grizzly and American black bears in British Columbia are probably intermediate hosts for S. canis
  
  • Highest risk in juveniles, especially cub of the years

Question 56

A recent study evaluated the serum proteins of giant pandas.

What is the scientific name of the giant panda?

Changes in prealbumin are suggestive of what?

What about changes in albumin?

What about changes in the alpha and beta globulin fractions?

What acute phase proteins live in the beta fraction? Which fraction are they in? Why does sample type matter in this fraction?

What proteins comprise the gamma globulin fraction?

Answer 56

Analysis of serum proteins in healthy giant pandas (ailuropoda melanoleuca) under managed care.
Comolli JR, Rivera S, Wang C, Cray C.
Journal of Zoo and Wildlife Medicine. 2022;53(2):442-447.

Electrophoresis is a practical diagnostic tool for the identification of changes in serum protein fractions, which can be associated with a variety of diseases. Protein electrophoresis studies in Ursidae are limited, and currently no published fraction values are available for the giant panda (Ailuropoda melanoleuca). The aim of this study was to describe the serum protein fractions in the giant panda using both capillary zone electrophoresis (CZE) and standard agarose gel electrophoresis (AGE) techniques. Serum samples from nine healthy giant pandas (n = 19) were used for this study. Samples were evaluated using CZE and standard AGE. The CZE procedure successfully resolved serum proteins into seven fractions: prealbumin; albumin; and α1-, α2-, β1-, β2-, and γ-globulin; while AGE separated serum into only six protein fractions: prealbumin; albumin; α1-, α2-, and β-globulins; and γ-globulin. These data will serve as a preliminary baseline for further studies and provide insight for the medical management of giant pandas.

Background
- Giant panda - vulnerable IUCN (habitat loss from deforestation, low repro rates, high dietary specialization, climate change
– Common issues: GI, renal, dental, infectious (distemper, listeriosis, demodicosis)
- Capillary zone electrophoresis: higher resolution, lower cost, and completely automated compared to agarose gel electrophoresis
- Prealbumin - negative APP, decreases with reduced protein synthesis from inflammation, stress, and malnutrition
- Albumin - functions for colloid osmotic pressure, molecular transport, buffering, free radical scavenging, coagulation, drug metabolism
– Major negative APP; decreases from loss (PLE, PLN) or reduced hepatic production
– Hyperalbuminemia usually dehydration
- Alpha and beta-globulin fractions increase with acute inflammation (highly sensitive)
- Beta-fraction - many acute phase proteins: B2-microglobulin, CRP, ferritin, hemopexin, plasminogen, angiostatin, fibrinogen (plasma only)
– Beta-1: increases with elevated transferrin in iron-deficiency anemia and elevated beta-lipoprotein with hypercholesterolemia
– Beta-2: complementary protiens
– Serum vs plasma B-fractions differ because fibrinogen is used for coagulation in serum
- Gamma-globulin fraction: IgG, IgA, IgM, IgD, IgE
- Hypogammaglobulinemia: fetal and pre-colostral sera, recurrent infections, immune deficiency
- Albumin/globulin ratio: helps to evaluate dysproteinemias

Key Points
- CZE successfully separated beta fraction into B1 and B2 - increased resolution compared to AGE
- Unable to make reference intervals due to low n

Conclusions
- Characterized EPH in giant pandas (very similar to other mammals), not technically reference intervals because of low n

Question 57

A recent study evaluated the morbidity and mortality of american black bears submitted to a rehabilitation center.

What demographics were most liklely to present?

What were the common causes of presenting?

What were the most common health issues these animals faces?

What were the most common findings on necropsy?

Answer 57

MORBIDITY AND MORTALITY OF FREE-RANGING AMERICAN BLACK BEARS (URSUS AMERICANUS) UNDERGOING REHABILITATION IN EASTERN TENNESSEE, USA, 1996–2021
Journal of Wildlife Diseases, 58(3), 2022, pp. 575–583

ABSTRACT: Free-ranging American black bears (Ursus americanus) often share habitat with humans and domestic animals, predisposing them to anthropogenic conflicts. Rehabilitation under professional care is a management option for orphaned, injured, and/or ill bears. Across several southeastern states, rescued bears are assessed and treated at the University of Tennessee and rehabilitated at Appalachian Bear Rescue (ABR). Records from 1996–2021 showed 337 bears (170 males, 166 females, 1 unknown) from nine states were admitted to ABR. Three bears were admitted twice, resulting in 340 admissions (42 neonates ,3 mo old, 206 cubs 3–12 mo, 87 yearlings 1–2 yr, and 5 adults .2 yr). Bears presented as orphans (58%), malnourished (24%), injured or ill (12%), or confiscated/other (6%). Individuals were returned to the wild (85%); died or were euthanized (12%); or were placed into professional care (3%). Of released bears, 195 had complete medical records available for evaluation; 31% were healthy upon intake while the remaining were treated successfully for malnutrition and internal parasites (49%), orthopedic (9%) and soft tissue injuries (5%), or other diseases (5%). Causes of death determined during necropsies performed (n¼30) were classified as trauma (50%), developmental (13%), undetermined (13%), malnutrition (13%), infectious or inflammatory (7%), and toxicosis (3%). Despite the lack of maternal care and high prevalence of malnutrition and trauma, most bears recovered to release with appropriate husbandry and medical care. This study provides a foundation for research to further improve care of rehabilitating black bears.

Intro
- This study describes morbidity and mortality of bears housed at Appalachian Bear Rescue (ABR) in Tennessee from its inception in 1996 through 2021, to ultimately guide health care and future research.

M&M
- Retrospective of records at ABR

Results
- 337 bears (170 males, 166 females, 1 unknown) from nine states (US) were admitted to ABR
- Bears were most likely to present in June and May, least likely to present in December and September
- Most likely to present in spring and summer and least likely to present in fall and winter
- Three bears were admitted twice, resulting in 340 admissions (12.4% neonates; 60.6% cubs; 25.6% yearlings; and 1.5% adults)
- Reason for intake: Most bears presented as orphaned neonates or cubs, or malnourished yearlings, with fewer bears injured or ill, confiscated, or other
- Outcomes: Individuals were returned to the wild (85%), died (6.2%), were euthanized (5.6%), or were placed into professional care (3.0%)
- There was no association between sex and reason for intake
- Orphaned neonates and cubs were statistically just as likely to return to the wild as were malnourished yearlings
- Injured or ill and ‘‘other’’ bears were significantly less likely to return to the wild compared with orphans and malnourished yearlings
- Causes of death or euthanasia determined by postmortem examination (n=30) were classified as trauma (50%, n=15), developmental (13%, n=4), undetermined (13%, n=4), malnutrition (13%, n=4), infectious or inflammatory (7%, n=2), and toxicosis (3%, n=1).

Discussion
- Despite an overall high survival rate for admitted bears, injured or ill bears were significantly more likely to be euthanized compared with orphaned or malnourished bears
- Traumatic injuries, undetermined causes of illness, and developmental abnormalities all decreased the likelihood of survival.
- Trauma was most common cause of mortality
- No bears died of a primary contagious infectious disease

Question 58

A recent study evaluated Dirofiliaria ursi selection sites in American black bears.

Where does this parasite typically affect bears?

What are teh most common sites for worm deposition?

How do microfiliarial levels vary throughout the day?

Answer 58

Addison EM, Pybus M.
POPULATIONS AND SITE SELECTION OF DIROFILARIA URSI (NEMATODA: ONCHOCERCIDAE) IN AMERICAN BLACK BEARS (URSUS AMERICANUS).
J Wildl Dis. 2022 Jul 1;58(3):584-591. doi: 10.7589/JWD-D-21-00155. PMID: 35439815.

Abstract
A total of 4,846 (84.5±87.15, 3-429: mean±SD, range) subadult or adult Dirofilaria ursi were recovered from 56 American black bears (Ursus americanus) in Ontario, 1975-77. Yearling bears had fewer worms than older bears; age classes greater than 2.5 yr had similar numbers of worms. Dead worms comprised 3.7% of all worms. There was one dead worm in total in 10 yearling bears and consistently more dead worms in older bears. The occurrence of worms within local sites in bears differed over time. Increasing numbers of worms appeared first in peritracheal sites (Site 1) following 1-3 seasons of transmission, in abundance in perirenal sites (Site 2) following the second season of transmission, and in lateral and ventral trunk and abdomen plus medio-proximal legs (Site 3) following three and four seasons of transmission. Few worms occupied other sites (Site 4). The proportion of worms recovered from the four sites was 46, 30, 19.8, and 3.9%, respectively. Dead worms comprised only 3.2% of worms in the first three definitive sites but 14% of worms in other sites. These data are consistent with primary, secondary, and tertiary site preferences for mature D. ursi in this species. Circulating microfilaremia in peripheral blood was periodic in 7/10 experiments and revealed a pattern of variable numbers during the day, highest in the evening and lowest during the night. The time of high density of microfilariae in peripheral blood was synchronous with the feeding cycle of Simulium venustum, the vector of D. ursi. Immediately postmortem, microfilariae were at highest densities in blood of lungs regardless of their relative density in peripheral blood. These data can direct diagnostic efforts to maximize detection of adult D. ursi in tissues and larvae in blood samples of naturally infected bears.

Key Points
- Relationship of black bears to their helminth parasites is poorly understood
- Likewise, patterns of microflira (MF) in circulating blood of bears over time and transmission of D. ursi from bears to the black fly vector (Simulium venustum) is poorly understood
- D. ursi is common in American black bears in N.A., mainly occurs in connective tissues (CT) in periesophageal and perirenal regions, and fat depots of the perirenal abdominal cavity, and adjacent to cervical and brachial lymph nodes, Adult females release MF into the blood, where they are picked up by black flies.
- There are variations in density of MF in blood depending on time of day, to optimize picking up by the vector
- Goal was to describe site distribution of adults as well as 24h periodicity of MF of D. ursi in naturally infected black bears
- 3 sites established for adult distribution: periesophageal - CT in the neck and pleural cavity anterior to the hilus of the lungs; perirenal - CT in peritoneal and pelvic cavities caudal to the adrenals; trunk site - lateral and ventral SC and intermuscular tissues of the thorax and abdomen and medio-proximal portion of the forelimbs
- 3-430 subadult or adult D. ursi were found per bear (mean 84)
- Yearling bears had fewer worms than older bears, similar #s in all four older bear age classes
- Dead worms were few in number 3.4%
- Site selection:
– Subadult/adult D. ursi were recovered from all three sites, the MC site was peritracheal (43%) > perirenal (30%) > trunk (20%)
– Worms also found in other places 4%: posterior pleural cavity, anterior peritoneal cavity, head, pericardium, back and latero-proximal and distal portion of legs
– In bears 2.5yr of age, significant increase in worms in the peritracheal site and perirenal site compared to worms 1.5yr of age
- MF: circadial periodicity (variations by time of day) occurred in 8/10 trials
– Highest MF in the late afternoon-early evening, lowest during the night and rising in the morning to variable levels
– MF in blood following death was highest in lung, spleen and kidneys compared to peripheral blood

Take home message
- No significant increase in worm burden in bears after 2.5yr of age, indicating ongoing mortality and resorption of worms as well as recruitment of new worms in the population
* The peritracheal site was occupied prior to other sites, had higher worm #s and is the primary definitive site, while the perirenal site is the secondary definitive site
* Peak time of circulating D. ursi microfilaria was during evening hours-peak feeding time for vectors
* It is increasingly likely that D. ursi will be encountered in sites other than peritracheal/perirenal with increasing age of the bear >2.5yr; a greater # of sites should be examined for subadult/adult worms in older bears compared to yearling bears
References: none

Question 59

A recent study evaluated the prevalence of mange in American black bears in New York State.

What is the etiologic agent in this species?

What sex was most likely to have mange? What was the primary complaint of the other sex?

What geographic area of New York was more likely to have mange?

What time period to most of these cases occur?

Answer 59

JWD 2022 58(4) 847-858
OCCURRENCE OF MANGE IN AMERICAN BLACK BEARS (URSUS AMERICANUS) IN NEW YORK STATE, USA

ABSTRACT: Mange, a parasitic skin disease caused by various species of mites, is found in freeranging wildlife populations and has been increasingly reported in American black bears (Ursus americanus) over the last decade in New York State (NYS), USA. Our goal was to describe the geographic, seasonal, and demographic factors associated with mange in this species in NYS. Our retrospective study used historic, opportunistic data from diagnostic necropsy records and visual sighting reports collected by the NYS Wildlife Health Program from 2009 to 2018. We used chisquare tests for independence and odds ratios to examine whether geographic location, year, season, sex, age, and reason for laboratory submission were associated with mange in bears. We used maps and seasonal analysis to investigate emerging patterns. We confirmed increased black bear mange reports in recent years. Necropsy data revealed more bears submitted to the laboratory because of mange, mainly caused by Sarcoptes scabiei; females were more likely than males to present with sarcoptic mange. We found that cases of mange in the Northern Zone were widely disseminated throughout the region, whereas cases in the Southern Zone were concentrated in two areas along the Pennsylvania border. Seasonally, mange cases showed peaks occurring in late spring to early summer and in fall. Our results were on the basis of available data; a comprehensive statewide surveillance program would be useful to better understand the apparent increase in mange and its potential impact on both the welfare of individual animals and the population of black bears in NYS. Additional research on the timing of transmission dynamics associated with females in winter dens may be helpful to wildlife managers to identify strategies to mitigate deleterious spread of the disease in black bears

Intro
- Sarcoptes scabiei is the most common etiology and is possibly related to immunocompromised condition after hibernation
- Aim: use necropsy and sighting data to assess the current status of mange in NYS black bears and determine relationships of mange cases with geographic location, year, season, sex, age

M&M
- Retrospective of submissions from 2009 to 2018 in NYS
- Necropsy records and reported sightings

Results
- Most bears were submitted for necropsy in spring whereas winter experienced the lowest proportion of submissions
- Parasitic diseases were the most common diagnosis among necropsy records.
- Trauma was the second most common diagnosis, with a higher proportion of males than females
- In the necropsy data, we found 54/150 (36.0%) cases of suspected mange
- odds of a bear having mange were four times higher in the Northern than in the Southern Zone
- cases of mange in the Northern Zone were widely disseminated throughout the region, whereas cases in the Southern Zone were concentrated in two areas along the Pennsylvania border.
- Female bears were 4.1 times more likely to have mange than males
- Males often had trauma as primary and mange as the secondary disease process
- No differences by age
- Often had poor BCS and other parasites and/or skin pathogens concurrent with mange
- 52 unique sightings of black bears with suspect mange reported
- Higher number of mange sightings in the summer, necropsy cases highest in the spring and fall

Discussion
- Not confirmed to be sarcoptes in all cases, could have been other mites or other skin pathogens
- The incidence of mange in bears generally increased across the study period but, demonstrates an inconsistent pattern.
- A seasonal pattern emerged, with mange cases peaking in late spring–early summer and showing slight increases in early fall and late winter
- Reports of mange mortalities in late spring–early summer might be a result of increased human activity and observation during this period, making identification of chronic mange in a bear more likely
- bears with mange may be driven to leave hibernation dens prematurely because of depleted fat reserves resulting in the late winter peak observed
- Increased susceptibility of female black bears may be linked to a decreased cellular immune response caused by female hormones or to the reduction of immune function in lactating females
- In addition, periods of implantation, gestation, or lactation could present challenges during hibernation, especially due to the high metabolic demand, making females more susceptible to mange