Avian Medicine > Sphenisciformes > Flashcards
Sphenisciformes Flashcards
Do pengiuns have crops?
No
What makes placing an IO catheter difficult in penguins?
No pneumatized bones, bones are heavy and dense (F8)
What type of supplementation may be necessary in penguins that are fed frozen thawed fish?
thiamine – thiaminase in fish and vitamin E (F8, Terio)
What is the causative agent of the most significant parasitic disease in captive penguins?
Plasmodium relictum or P. elongatum (avian malaria) (F8, Terio)
What is the treatment of choice for avian malaria (plasmodium)?
chloroquine and primaquine (F8)
What flavivirus should you vaccinate pegnuins for?
West nile virus (and sometimes EEE) (F8)
What type of temperature dysregulation most commonly affects penguins during anesthesia?
Hyperthermia (West)
What are 2 anatomic features that make intubation of penguins difficult?
Short trachea/early bifurcation and crista ventralis
What anatomical change can occur in penguins if they are kept in fresh water without salt supplementation?
Atrophy of the salt gland (Terio, F8)
What antifungal has caused neuro and pulmonary toxicity in penguins?
voriconazole (Terio)
What antifungal has caused hepatotoxicity in penguins?
Itraconazole (terio)
What are some predisposing factors for pododermatitis in penguins?
sedentary behavior, decreased swimming and prolonged standing on abrasive, hard, moist, or fecal contaminated flooring (Terio)
What condition of the uropygial gland is common in penguins
Impaction/infection - candida commonly isolated (Terio)
What are common sites of malignant melanoma in penguins?
skin of foot or hock, subcutis and subjacent muscle near beak and oral cavity (Terio)
What 2 forms of avipoxvirus are seen in penguins?
cutaneous and diphtheritic (Terio)
What is the causative agent of the most significant fungal disease in penguins?
Aspergillus fumigatus (Terio)
What genus is the vector of avian malaria?
culex (terio)
Describe the life cycle of avian malaria
Sporozoites in infected saliva of female mosquitoes –> injected into host and enter reticuloendothelial cells –> develop into first generation exoerythrocytic meronts –> undergo asexual multiplication and form merozoites –> host cell rupture releases merozoites into blood and results in additional infection of reticuloendothelial cells or infection of erythrocytes (proceeding to erythrocytic merogony or gametogony) –> in erythrocytes, merozoites develop into trophozoites –> differentiate into either erythrocytic meronts or gametocytes (macrogametocytes or microgametocytes) –> gametocytes remain inside erythrocytes until ingestion by insect host where sporogony takes place (Terio)
What is penguin diphtheria?
diphteritic stomatitis and/or esophagitis and/or enterocolitis - etiology unknown, affects young chicks
Describe factors affecting abnormal molting in the managed African penguin population in North America?
FACTORS AFFECTING ABNORMAL MOLTING IN THE MANAGED AFRICAN PENGUIN (SPHENISCUS DEMERSUS) POPULATION IN NORTH AMERICA
Golembeski M, Sander SJ, Kottyan J, Sander WE, Bronson E.
Journal of Zoo and Wildlife Medicine. 2020 Jan;50(4):917-26.6.
Background:
Penguins undergo a catastrophic molt in three phases over 96 days
Gain 31% body weight during premolt to have enough energy stores
In the wild, molt occurs in the summer after chick rearing
Sex hormones drop rapidly just prior to molting
Thyroxine stimulations feather growth; androgens and estrogens inhibit feather development
Thyroxine, medroxyprogesterone acetate, and estradiol have shown varying success in inducing molt in penguins
Estradiol induces molt 60-90 days after administration when drop in estradiol mimics natural hormone changes
Key Points:
The chance of abnormal molt was increased with:
Increasing age
Freshwater pools
Allowed to rear chicks for < 3 weeks
Fed a diet with <3 or > 5 species of fish
Artificial lighting
Treatment with melatonin implants was successful (82%) but medroxyprogesterone acetate implants were not
Some other successful treatments (n=1 each): UV light, leuprolide, SSD, marbofloxacin, high-fat diet
25% success rate on levothyroxine
Conclusions: Abnormal molt in African penguins is associated with increasing age, freshwater pools, shortened chick rearing time, and artificial lighting.
What happened to plasma levels of vit B1, A1, D, and E during supplementation in penguins?
PLASMA CONCENTRATIONS OF VITAMIN A1, B1, D3, AND E IN HUMBOLDT PENGUINS (SPHENISCUS HUMBOLDTI) BEFORE AND AFTER DIETARY VITAMIN SUPPLEMENTATION OF THEIR FISH DIET.
Bos JH, Klip FC, Kik MJL.
J Zoo Wildl Med. 2018 Sep;49(3):732-737.
Methods:
Adult humboldt penguins (n=17) housed together at the Ouwehand Zoo
Vitamin supplementation discontinued for 6 months prior to study
The batch of frozen-thawed fish fed in this study was deficient in vitamin B1 and E
Treatment group received oral supplementation of vitamins A1, B1, D3, and E (α-tocopherol) injected into fish
Control group received no vitamin supplementation
Blood drawn on day 0 and day 70 to assess for plasma vitamin levels
Key Points:
After 70 days, the plasma levels of supplemented penguins showed…
Vitamin B1 increased
Vitamin A1 decreased
Vitamin D and E did not change
There was no significant changes in the control group
Vitamin A is stored in the liver, and plasma levels are not a well-correlated
Supplementation of lipid-soluble vitamins (ADEK) can inhibit absorption
May be the reason why no increases were seen in this study
Conclusions: It is important to supplement frozen-thawed fish fed to penguins with vitamin B1 and supplementation of vitamin E. Vit D may be considered based on analysis of penguin plasma levels and the analysis of each batch of fish.
Captive little penguins have appeared to be at increased risk of developing what bacterial disease?
DIAGNOSIS AND MANAGEMENT OF MYCOBACTERIOSIS IN A COLONY OF LITTLE PENGUINS (EUDYPTULA MINOR)
Anne E. Rivas et al.
Journal of Zoo and Wildlife Medicine 50(2): 427–436, 2019
Background:
Signs of mycobacterium are often nonspecific with birds appearing aclinical until severe pathology is present
Most susceptible species: Anseriformes, Gruiformes and Galliformes
Case Series: 16 penguins housed indoors included in a multidetector computed tomography study of the respiratory tract. 5 penguins had nodular changes to the lungs (asymptomatic)
Mortalities: 3 cases died
M avium hominisuis isolated from 1 necropsy case (case 2)
Only 1 pathogenic isolate found from 1 live bird (M intracellularae)
None isolated from environment
All remaining birds were treated with rifampin, ethambutol, clarithromycin and enrofloxacin
Twice weekly scrubbing of the enclosure was performed with bleach
Recheck MDCT 4m after treatment showed improvement.
13m after treatment, MDCT repeated again showed full resolution in all but one bird.
Key Points:
Success in these cases was likely due to early initiation of treatment
Case that died with treatment had a large granuloma- drugs likely could not penetrate the bacteria
Goal of decontamination protocols was to disrupt biofilms.
Stress from transport or quarantine may have contributed or the penguins came with the infection.
Different species isolated demonstrate a lack of common source.
MDCT identified early pulmonary granulomas in birds in this study that were neg on other diagnostic tests
Conclusions: Captive little penguins appear at increased risk of developing mycobacteriosis. Successful management can be performed if diagnosed early with the aid of MDCT. Culture of gastric washes can detect pulmonary infections.
Clinical signs of hypovitaminosis A in birds? Penguins?
SUSPECTED HYPOVITAMINOSIS A–ASSOCIATED SALT GLAND ADENITIS IN NORTHERN ROCKHOPPER PENGUINS (EUDYPTES MOSELEYI)
Naylor AD, Pizzi R, Cole G, Morrison LR, Girling SJ.
J Zoo Wildl Med. 2018 Jun;49(2):420-428.
Supraorbital salt-excreting glands help with homeostasis by excreting sodium chloride
Salt gland size is dependent on salt intake (e.g. will atrophy if penguin is kept in freshwater)
In penguins, supraorbital salt glands are dorsal to orbit and drain into the nasal cavity
Granulomatous salt gland adenitis reported in ducks, Humboldt penguins, and little penguins with bacterial infection
Salt gland squamous metaplasia in turkeys with vitamin A deficiency
Cases:
At Royal Zoological Society, five adult Northern rockhopper penguins develop supraorbital swelling within 6 weeks
Some birds also had hyporexia, lethargy, epiphora, chemosis, and/or vomiting
Did lots of diagnostics, including exploratory surgery to remove tissue
The next year post-molt, two cases recurred and two new ones occurred
Histo of select cases showed granulomatous inflammation and squamous metaplasia
All cases occurred towards the end of molt
Entire rockhopper colony and frozen fish stores had very low vitamin A and E levels
Vitamin levels in penguin improved after one year of oral vitamin A and E supplementation
Key Points:
Food-stock management is crucial and intermittent vitamin testing may be recommended
Fat-soluble vitamins can still degrade in frozen fish because peroxidation of fat is slowed, not completely halted
Krill is a diet item that is high in vitamin A and E, but this institution had trouble getting penguins to accept it
Vitamin A deficiency in birds can cause squamous metaplasia, choanal papillae blunting, keratinaceous blockage of sinuses, and reproductive failure
Thought that the supraorbital swelling were due to blockage of the ducts with keratinaceous debris
Hypervitaminosis A may be a risk factor for cataract formation in macaroni penguins
Vitamin A status may be at lowest at the end of molt because all of the cases were during that time
Studies in wild penguins have varying results on when retinol is lowest in relation to molt.
Vitamin E deficiency can also cause skeletal and cardiac myodegeneration, steatitis, and reproductive failure
Conclusions: Suspected hypovitaminosis A caused salt gland adenitis in Northern rockhopper penguins due to extended storage of frozen fish.
Prognostic indicators of immature rehabilitated african penguins in south africa? Which group had the highest release rate (condition and age)?
PROGNOSTIC INDICATORS OF IMMATURE REHABILITATED AFRICAN PENGUINS (SPHENISCUS DEMERSUS) IN SOUTH AFRICA
Vanstreels RE, Parsons NJ, Pistorius PA, Schaefer AM.
Journal of wildlife diseases. 2019 Oct;55(4):758-69.
Survival rates: blues (fledglings, 77%) > juveniles (70%) > chicks (69%)
Hematocrit was lower in abandoned chicks and blues and in injured blues and juveniles
Total protein was lower in chicks that were preemptively removed, oiled blues, and debilitated juveniles.
Released individuals generally had higher BCS, hematocrit, and TP than those that died
Risk factors were death:
Low hematocrit in chicks (<30%) or blues (<37%)
Low TP in chicks (< 4 g/dL), blues (< 4 g/dL), and juveniles (< 4.6 g/dL)
Debilitation, injury, and molt (compared to oiled)
High TP (> 5.8 g/dL) was protective for natural death in chicks
Oiled juveniles had highest release rate
Conclusions: Risk factors for death in rehabilitated immature african penguins include low hematocrit and low total protein.
What is the number one cause of admission of adult african penguins to wildlife rehab centers?
Admission during what time of year more likely to be released?
Factors associated with natural death? Factors associated with euthanasia?
PROGNOSTIC INDICATORS OF REHABILITATION OUTCOMES FOR ADULT AFRICAN PENGUINS ( SPHENISCUS DEMERSUS).
Parsons NJ, Vanstreels RET, Schaefer AM.
J Wildl Dis. 2018 Jan;54(1):54-65.
Overall release rate = 83.3%
70% of deaths occurred within the first week of admission
Females more likely to be euthanized (66% of euthanized cases)
Reasons for admission: oiling >>> injury > debilitation > molt > other
Oiled penguin release rate = 93%
Often beach themselves, are readily visible to public, and have good body condition
Injury penguin release rate between 52-71% based on location of injury
Duration of stay was longest in injuries on chest, back, and abdomen compared to neck, tail, legs, flipper.
Molted penguins had variable body masses based on time in molt
Molt can be arrested if not enough energy stores beforehand
Consider treating with hormone supplement and high-protein nutritional supplement
More likely to be release if admitted in winter, compared to spring and summer
Often admitted with higher body condition score in winter
Often lower BCS after spring/summer breeding season
Plasmodium infection rate = 6.5%
In contrast with recent study in wild penguins that did not find Plasmodium o
Important to minimize time in rehabilitation, control mosquitos, and treat Plasmodium infections early
Penguins were more likely to suffer natural death if:
Admitted during summer and spring
Admission due to molt or debilitation
Low body mass on admission
Low HCT or TP on admission
Positive Plasmodium diagnosis during rehabilitation
Penguins were more likely to be euthanized if:
Admitted during spring
Low TP on admission
Reason for admittance besides oiling (injury, molt, debilitation, other)
Injury penguin is 13.14x more likely to be euthanized than an oiled penguin
Conclusions: Penguins are more likely to die in rehabilitation if low PCV or body weight on admission, presentations due to molt or debilitation, or develop Plasmodium infection, or admitted in spring.
Compared to normal penguins, asper penguins had what changes to the following? albumin-globulin, prealbumin, alpha 1 globulins, alpha 2 globulins, beta and gamma globulins, 3-hydroxybutyrate?
Penguins with aspergillosis had increases in which of those two?
APPLICATION OF 3-HYDROXYBUTYRATE MEASUREMENT AND PLASMA PROTEIN ELECTROPHORESIS IN THE DIAGNOSIS OF ASPERGILLOSIS IN AFRICAN PENGUINS (SPHENISCUS DEMERSUS).
Desoubeaux G, Rodriguez M, Bronson E, Sirpenski G, Cray C.
J Zoo Wildl Med. 2018 Sep;49(3):696-703.
Aspergillus spp. Is a fungal airborne infection that can affect birds
Clinical signs: respiratory, neurologic, nonspecific lethargy
Noninvasive and antemortem diagnostics are difficult to interpret
Uninfected penguins may have high anti-Aspergillus antibodies
Radiography can have low specificity
Protein electrophoresis can reveal information about disease processes based on changes in proteins
Albumin = a negative acute phase protein
Significance of prealbumin is not known in birds, but may be a negative acute phase protein
Gamma globulin increase corresponds with humoral immunity
Psittacines have beta-globulins as the dominant globulin. Penguins have alpha 2 and beta globulins
3-hydroxybutyrate, lipids, and fatty acids are increased in falcons with Aspergillus fumigatus compared to healthy
3- hydroxybutyrate is thought to reflect the need for energy associated with infection
Key Points
Half of the aspergillosis penguins had weight loss, anorexia, or severe regurgitation
No difference in anti-Aspergillus nor galactomannan antigen between groups
Compared to normal penguins, aspergillosis penguins had…
Lower albumin-globulin, prealbumin, and alpha-1 globulins
Higher alpha-2, beta, gamma globulins, and 3-hydroxybutyrate
Compared to non-aspergillosis inflammation penguins, aspergillosis penguins had…
Higher alpha-2 globulins and 3-hydroxybutyrate
When you combine 3-hydroxybutyrate, alpha-2 globulins, and beta globulins, specificity (97.9%) and negative predictive value (80.5%) increases.
Conclusions: 3-hydroxybutyrate may be used in conjunction with protein electrophoresis for the diagnosis of aspergillosis in African penguins.
Where were the highest fungal loads detected around a penguin exhibit?
Which Asper organism was most susceptible to terbinafine?
ENVIRONMENTAL FUNGAL LOADS IN AN INDOOR-OUTDOOR AFRICAN PENGUIN (SPHENISCUS DEMERSUS) EXHIBIT.
Rivas AE, Dykstra MJ, Kranz K, Bronson E.
J Zoo Wildl Med. 2018 Sep;49(3):542-555.
Background:
Penguins are highly susceptible to aspergillosis
Commonly A. fumigatus; also A. flavus, niger, glaucus, and nidulans
Largest N. American breeding colony of African penguins at the Maryland Zoo with a brand new exhibit
Air-handling system has non-HEPA pleated filters with a minimum efficiency reporting value (MERV) of 8
Key Points:
Outdoor samples generally had more fungal spores than indoor samples
Outdoor total fungal loads, but not Aspergillus loads, were significantly correlated with monthly temperature
Not correlated with monthly precipitation
The highest fungal load was collected from the tree planter site in the public area
Try to minimize plants in the penguin exhibit
Seasonal trends showed more fungus in warmer months with increasing humidity and temperature
Non-Aspergillus species isolated = Chrysonilia sitophila, Cladosporium spp., Penicillium spp., and yeasts
Chrysonilia sitophila often overgrew the plates, so they had to culture everything at 37 C
All Aspergillus samples tested were susceptible to voriconazole, itraconazole, and terbinafine
A. niger was the most susceptible to terbinafine and the least susceptible to voriconazole and itraconazole
Nest materials grew C. sitophila at all time points but no Aspergillus
Towards the beginning of the study, the air system was turned off accidentally and the fungal loads spiked
Suggests that the air system is effective in decreasing the indoor fungal load
Conclusions: When an appropriate air-handling system is in place, Aspergillus fungal loads are lower indoors than in the outdoor portions of a penguin exhibit.
What was observed in regards to step width in terms of penguins considered to be abnormal when on a pressure-sensitive walkway?
OBJECTIVE GAIT ANALYSIS IN HUMBOLDT PENGUINS (SPHENISCUS HUMBOLDTI) USING A PRESSURE-SENSITIVE WALKWAY
Sheldon JD, Adkesson MJ, Allender MC, Balko JA, Bailey RS, Langan JN, Chinnadurai SK.
Journal of Zoo and Wildlife Medicine. 2020 Jan;50(4):910-6.
Background:
Kinematic and force-plate analysis require non-portable, expensive equipment and markers placed on patient
Pressure-sensitive walkways measure multiple steps in a single trial and can be portable
Key Points:
Left step width was larger in abnormal penguins (may reflect right-sided lameness)
No difference between laterality and sex
Conclusions: You can measure a penguin’s gait with a pressure sensitive walkway
General GI transit time for penguins? Location of ventriculus and how to differentiate on endoscopy?
THE RADIOGRAPHIC AND ENDOSCOPIC ANATOMY AND DIGESTIVE MECHANISMS OF CAPTIVE AFRICAN PENGUINS (SPHENISCUS DEMERSUS)
Kline S, Kottyan J, Phillips J, Wack A, Pate N, Bronson E.
Journal of Zoo and Wildlife Medicine. 2020 Jun;51(2):371-8.
Esophagus and proventriculus have longitudinal folds
Both located on left side
Proventriculus has gastric papillae on endoscopy
Ventriculus is in caudal coelom
Koilin (tough green polysaccharide-protein-phospholipid complex) on endoscopy
Histo is more accurate than gross examination for koilin thickness measurement
Intestines are to the right and dorsal of ventriculus
Total barium GI transit time 17-70 min
Completely cleared within one day.
Conclusions: Penguins’ ventriculus is caudal in the abdomen.
Relative half-life of meloxicam in penguins? Duration of action between 0.5 mg/kg and 1 mg/kg?
Pharmacokinetics of a Single Dose of Oral and Intramuscular Meloxicam in African Penguins (Spheniscus demersus)
Morrison J, Greenacre CB, George R, Cox S, Martín-Jiménez T.
Journal of avian medicine and surgery. 2018 Jun;32(2):102-8.
Meloxicam is excreted in urine and feces and bile
Oral meloxicam 1 mg/kg in African penguins (compared to 0.5 mg/kg IM) had:
Longer Tmax (12 h vs. 1 h)
Longer duration of action (60 h vs. 24 h)
Both had long half-life (28-32h)
Similar to pelicans (36h)
Recommended dosing:
1 mg/kg PO q48h
0.5 mg/kg IM q24h
Conclusions: Penguins have a longer half life of meloxicam than most other birds.
Which Babesia spp was observed in penguins vs cormorants in a study evaluating primaquine tx?
Outcome of treatments?
Empirical Primaquine Treatment of Avian Babesiosis in Seabirds
Ralph Eric Thijl Vanstreels, Renata Hurtado, Albert Snyman, David G. Roberts, Nola J. Parsons, Pierre A. Pistorius
J. of Avian Medicine and Surgery, 33(3):258-264 (2019).
Key Points:
No toxic or adverse effects noted with primaquine treatment
Penguins - <1% positive by day 14
Relapses in 3% (primarily chicks)
Babesia peircei
Cormorants - parasitemia decreased rapidly during first 3 days
No positive blood smears after 6 days.
No relapses
Babesia ugwidiensis
1mg/kg PO q24h x 10d - but no PK available
100% effective in Cape cormorants
99.6% effective in African penguins
Conclusions: Primaquine daily for 10 days cleared Babesia infections in cormorants and African penguins.
Mechanism of voriconazole?
Adverse effects reported in penguins?
Effects of 5 mg/kg voriconazole PO SID x 8 days on African penguins?
PHARMACOKINETICS OF ORALLY ADMINISTERED VORICONAZOLE IN AFRICAN PENGUINS (SPHENISCUS DEMERSUS) AFTER SINGLE AND MULTIPLE DOSES
Hyatt MW, Wiederhold NP, Hope WW, Stott KE.
Journal of Zoo and Wildlife Medicine. 2017 Jun;48(2):352-62.
Background:
Aspergillosis is common in African Penguins due to:
High fungal spores in the environment
Immunosuppression
Stress
Inadequate nutrition
Poor ventilation
Older age or underlying disease
Voriconazole = second generation triazole antifungal agent
MOA: inhibits the fungal cytochrome p450 enzyme and inhibits biosynthesis of ergosterol
Eliminated via liver
Adverse clinical effects in penguins: anorexia, lethargy, depression, weakness, ataxia, paresis, blindness, seizures
Studies in other penguins
Magellanic penguins: 5mg/kg PO SID x 5 days, then off for 1 day
Humboldts: 5 m/gkg PO SID did not reach therapeutic levels
African penguins: 2.5-8 mg/kg PO once did not produce toxicity
Key Points:
Tmax longer when given with food
Similar to red-tailed hawks
Half-life longer than other species
Took 4-7 days to reach therapeutic levels
Conclusions: Voriconazole 5mg/kg PO SID x 8 days in African penguins did not result in toxicity and resulted in appropriate concentrations for days 4-7.
Effects of a single 20 mg/kg dose of itraconazole (Itrafungol) on African penguins?
Preliminary Pilot Study of Itraconazole After a Single Oral Dose of a Veterinary Formulation Solution in African Penguins (Spheniscus demersus)
Zalesak SM, Sanchez CR, Pich AA, Papich MG.
Journal of Avian Medicine and Surgery. 2020 Mar;34(1):52-6.
Itraconazole’s high lipophilicity requires low gastric pH with a meal for dissolve → inconsistent oral absorption
Commercial formulations add hydroxypropyl-β-cyclodextrin in overcome the solubility issues
Sporanox (human formulation) is much more expensive than Itrafungol (new cat formulation)
Key Points:
African penguins administered a single 20 mg/kg dose of itraconazole (Itrafungol) had measurable levels
56% of penguins had levels over 1 mcg/mL for 12 hours
Tmax = 5 hours, half-life = 8 hours
No adverse effects
Need more data before they can prescribe a dosing regimen.
Conclusions: No adverse effects and promising PK for African penguins administered a single dose of 20 mg/kg itraconazole.
Was there a correlation between hen and egg titers to WNV following vaccination?
THE PASSAGE AND DURATION OF ANTIBODIES TO WEST NILE VIRUS IN HUMBOLDT PENGUINS (SPHENISCUS HUMBOLDTI)
Cushing AC, Dubovi E, Erb HN, Georoff TA, Abou-Madi N.
Journal of Zoo and Wildlife Medicine. 2017 Mar;48(1):159-63.
Background:
West Nile virus, a Flavivirus with a mosquito vector, has caused significant avian mortalities.
Humboldt penguins are susceptible to WNV, even if housed indoors.
Seroconversion has been proven in Humboldt penguin adults receiving a WNV killed vaccine.
Passage of antibodies from hen to offspring is via egg yolk.
Key Points:
The median titer of recently boostered hens was the same as those not recently boostered.
Positive correlation between hen titers and egg titers.
All chicks had detectable antibody titers at 14 and 28 days.
No association between hen titer and chick titers at 14 days.
Some chicks (2/7) had undetectable titers at 42 days
Most chicks (6/7) had undetectable titers at day 84.
Correlation of hen and eggs titers proves passive antibody transfer via yolk.
In this study, boosters did not increase hen titers, though boosters may still be beneficial.
WNV maternal antibodies longer lasting in Humboldt penguins compared to flamingos (30% undetectable at 28 d)
Recommend vaccinating chicks at 42 days, in addition to 56 and/or 80 days
Conclusions: Humboldt penguins can pass maternal West Nile virus antibodies to their chicks via yolk.
What two parameters differed in venous vs arterial sampling of blood gases in anesthetized magellanic penguins?
Dutra, G. H. P., Araujo, G. S., da Silva, A. N. E., Nascimento, C. L., & Carregaro, A. B. (2019). Venous and arterial acid-base analysis of magellanic penguins (spheniscus magellanicus), awake and anesthetized by isoflurane. Journal of Zoo and Wildlife Medicine, 50(1), 262-265.
- Compared anesthetized vs. non-anesthetized venous acid-base blood samples and venous vs. arterial anesthetized acid-base blood samples of magellanic penguins
- Anesthetized penguins had transient apnea, then hypercapnia, likely due to inhaled anesthetic mediated respiratory depression
- Leads to respiratory acidosis (higher PCO2 and HCO3, lower pH levels)
- Significant differences in venous vs. arterial samples- PO2 and SO2 concentrations- arterial blood is saturated with oxygen, venous blood is not
- There were no significant differences in awake vs. anesthetized animals for pH, BE, Na+
- Overall- both venous and arterial samples can be used to evaluate acid-base in penguins as long as you are cautious in interpreting PO2 and SO2
Prognostic indicators for survival in Af penguin chicks? What was considered to be the single biggest factor correlating with survival?
Fustukjian, A. H., Flower, J. E., Sirpenski, G., & Tuttle, A. D. (2018). Prognostic indicators for survival in African penguin chicks (Spheniscus demersus): A retrospective analysis. Zoo biology, 37(5), 347-353.
- No significant relationship between egg hatch order and survival beyond 7 days was detected
- No major difference between hand reared and parent reared chick survival
- Majority of African penguin chick mortalities seen in 1st week
- >80% of all pre-fledgling deaths occurred on or before day 7
- Respiratory and gastrointestinal disease most commonly identified
- Single biggest factor correlating with survival - chick weight at time of hatching
- 60.5-66.3g+ chicks had significantly higher likelihood of surviving beyond 7 days, and chicks surpassing this were much more likely to survive to fledge
- Correlations between egg weight, dam weight, and chick hatch weight may be useful in identifying problem chicks early
Which diagnostic has provided reliable and potentially earlier diagnosis of pulmonary granulomas in penguins?
Rivas, A. E., Fischetti, A. J., Le Roux, A. B., Hollinger, C., Oehler, D. A., & Paré, J. A. (2019). Standing computed tomography in nonanesthetized little penguins (Eudyptula minor) to assess respiratory system anatomy and monitor disease. Journal of Zoo and Wildlife Medicine, 50(2), 396-404.
- Little penguins = smallest penguin species
- Aspergillosis and nontuberculous mycobacteriosis are common respiratory diseases
- Difficult to diagnose with rads
- MDCT = multidetector CT = high-quality images in a short time
- Lung or air sac volume did not differ between healthy vs. birds with pulmonary granulomas; lung density did differ
- Greater mean, median, maximum lung density greater in birds with pulmonary granulomas
- Standing position also allows for evaluation in a more normal anatomic position
- Mass-specific lung volume was almost identical to adelie penguins, king, emperor penguins BUT little penguins had lower air-sac volume than the other species
- CTs provided more accurate assessment of respiratory system than standard rads- eliminates superimposition
Takeaways:
- Provided references for baseline information on lung density and lung/air sac volumes
- Provided reliable and potentially earlier diagnosis of pulmonary granulomas but air sac thickening/plaques could be missed
A recent study evaluated point of care ketone meters to estimate serum B-hydroxybutyrate concentrations in healthy African penguins.
What is the scientific name of the African penguin?
What leads to the production of B-hydroxybutyrate?
How did the POC meters perform against lab analyzers?
AJVR 2022 83(6):ajvr.21.11.0192
Point-of-care ketone meters may be used to estimate serum β-hydroxybutyrate concentrations in healthy African penguins (Spheniscus demersus)
Key Points:
- Ketosis = insufficient supply of glucose leads to increased β-oxidation of fatty acids
– Leads to production of ketone bodies (acetone, acetoacetate, and β-hydroxybutyrate)
– Ketone bodies used as an alternative primary energy source
- King penguins, like other penguin species, will fast for periods of 5 months in the winter
– Plasma β-HB concentrations are considerably elevated by prolonged fasting and molting
- Although POC devices overestimated β-HB concentration levels in comparison to reference laboratory, random error was low and laboratory versus device values correlated well
- WB, not plasma, should be used for measurement of β-HB concentration on POC meters.
- The use of POC devices for β-HB concentration may be acceptable when laboratory analyzers are not available
A recent study compared plasma trace elements between 2 captive humboldt penguin populations.
What is the scientific name of the humboldt penguin?
How did the values differ between the two groups?
Journal of Avian Medicine and Surgery, 36(4) : 362-3
Comparison of Plasma Trace Elements Between 2 Captive Humboldt Penguin (Spheniscus humboldti) Populations
Key Points:
* Concentrations of some trace elements in plasma can differ between 2 captive populations of penguins, and the study provided new data on trace element concentrations in captive Humboldt penguins
* Could be water source differences or enclosure differences
A recent study described mefloquine toxicity in a colony of Humboldt penguins.
What is the scientific name of humboldt penguins?
What is the etiologic agent of avian malaria?
- What. isits primary vectors?
What is typically used for prevention and for treatment of avian malaria?
What dose of mefloquine did they use?
What effects did they see?
Suspected Mefloquine Toxicity in a Colony of Humboldt Penguins (Spheniscus humboldti)
Scala et al
Key Points:
- penguins are mainly susceptible to Plasmodium relictum and Plasmodium elongatum
- Mosquitoes (Diptera: Culicidae) are the primary vectors for these parasites, and Culex species are considered to be the most significant vectors in the transmission to captive penguins.
- Primaquine was previously used but was no longer available
– Other options for avian malaria prevention in penguins include mefloquine once a week or sulfadiazine–folic acid–pyrimethamine every 2–3 days.
– Chloroquine and doxycycline can also be used but are usually reserved for therapeutic purposes to treat penguins that have been diagnosed with avian malaria
- They performed a pilot study to test two doses – 5mg/kg and 30mg/kg 🡪 30mg/kg had better MIC for plasmodium
- Then 19 Humboldt penguins (at a zoo in France) were given 125mg mefloquine once per week
– 4-6th weeks – regurgitation seen
– After 5th dose one penguin found dead
– After week 7, they performed plasma concentrations, found it to be high and stopped the treatment
– Several more penguins died after the least treatment (long half-life)
- They switched to sulfadiazine-folic acid-pyrimethamine q 2-3 days after that and have had no deaths since
- Mefloquine is a quinoline derivative, similar to other antimalarial drugs such as chloroquine and primaquine.
– Mefloquine is selectively active against the intraerythrocytic stages of parasite development (schizonts), without activity against gametocytes or the intrahepatic stages.
A recent study investigated the prevalence. ofeimeria in wild yellow-eyed penguins.
What is the scientific name of the yellow-eyed penguin?
How prevalent was Eimeria in the populatinos studied?
What were the clinical signs of affected birds?
PREVALENCE AND PATHOGEN LOAD OF EIMERIA IN WILD YELLOW-EYED PENGUINS (MEGADYPTES ANTIPODES) AND THE MORPHOLOGIC CHARACTERIZATION OF A NOVEL EIMERIA SPECIES
Emily Kay,1,2,4 Melanie J. Young,3 Chris Muller,1 Laryssa Howe,1 Wendi Roe,1 and Brett D. Gartrell1
Journal of Wildlife Diseases, 58(4), 2022, pp. 836–846
Key Points:
- Prevalence of ~75% in sub-Antarctic population and ~60% in mainland population 🡪 weak evidence for difference in prevalence of Eimeria and pathogen load between the two sites
– No difference in BCS/mass between Eimeria positive and negative birds
– Suspected novel Eimeria sp based on morphology
- High prevalence and pathogen load of a novel Eimeria sp in both populations of Yellow eyed penguins with apparent mild/absent clinical effect of the organism
A recent study described the detection of spheniscid alphaherpesvirus 1 in free-ranging humbold penguins.
What is the scientific name of the humboldt penguin?
What diseases have been found in the Punta San Juan population?
What are the typical clinical signs of this virus?
HOw prevalent was it in the population?
DETECTION AND PREVALENCE OF SPHENISCID ALPHA-HERPESVIRUS-1 (SpAHV-1) IN A SAMPLE OF HUMBOLDT PENGUINS (SPHENISCUS HUMBOLDTI) AT PUNTA SAN JUAN, PERU.
Angles R, Adkesson MJ, Cárdenas-Alayza S, Adamovicz L, Allender MC.
Journal of Zoo and Wildlife Medicine. 2023;54(1):159-63
Key Points:
- Humboldt penguins - Chile and Peru
– Previous study found titers for infectious bronchitis virus, avian reovirus, paramyxoviruses, Salmonella pullorum
- Most avian herpesviruses in non-commercial birds - gammaherpesvirinae
– Nonspecific signs, respiratory, or neurological
– Humboldt, African, Magellanic, little blue penguins found to have inflammation and intranuclear viral inclusions, when sequenced found novel avian alpha-herpesvirus, spheniscid alpha-herpesvirus 1 (SpAH-1)
- Despite reports of Spheniscid alpha-herpesvirus 1 in penguins, only 1/62 Humboldt penguins in Peru tested positive on PCR of tracheal swab
