Aquatic

Question 1

Anatomic adaptations of the cardiovascular system of cetaceans to support diving, breath-holds, and temperature conservation

Answer 1

large distensible veins, venous sinuses, venous valves in the lungs, portal triads of the liver, venous sphincter in the common hepatic vein at the junction of the inferior vena cava below the diaphragm, and

temperature countercurrent system: rete mirabile (meshwork of arteries and veins between the horacic vertebral bodies) and periarterial vascular rete - allow peripheric vasoconstriction and still perfuse main organs with warm, oxygenated blood. Because of that true venous or arterial samples from peripheric vessels is difficult, most common site for collection is a superficial periarterial vascular rete (dorsal and ventral midlines of fluke blades).

Question 2

Adaptations of respiratory system of cetaceans

Answer 2

Anterior to the carina is a right-sided accessory bronchus, leading to the anterior portion ofthe right lung lobe

Complete tracheal and bronchial cartilaginous rings extending to deep bronchioles

Nonseptate, nonsegmented lungs covered by a thick, dense, viceral pleura

Lungs have great amount of elastic tissue

Question 3

Gastrointestinal system cetaceans

Answer 3

Odontocetes (toothed whales): 3 chambered stomach:

1) forestomach - muscular chamber, collects the meal and intiates mechanical digestions
2) fundic - glandular
3) pyloric chamber and duodenal ampula

*Mysticete (baleen whales)

Question 4

Housing requirements of marine mammals

Answer 4

Established by the Animal Welfare Act written and curated by the US departmnet of Agriculture

Enforced by the Animal Plant Health Inspection Service

cetaceans - Size is based on depth, volume, surface area, and on a “minimun horizontal distance”. Salinity 27 to 32 ppt, coliform not more than 1000 per 100 ml water.

Chlorine based oxidandts (below 1 ppm) and ozone are the main sterilizing agents.

Question 5

Feeding of cetaceans

Answer 5

Individual quick frozen fish is preferable

Should remain frozen below -2C

Air thawing 24 h prior to feeding under refrigeration (not more than 5C) - water thawing promotes bacerial growth and reduce nutritional value

feed whole fish

Mackeral and Tuna - incriase possibility of scombroid poisoning (histamine production on fish)

Supplement with vit A, E, and B complex (should be addded right before feeding because of thaminase activity within the fish)

Question 6

Chemical restraint of cetaceans

Answer 6

It is limmited due to anatomy and physiology challenges

Sedation with benzodiazepine

**Flumazenil - responsive atrial fibrilation in selected cases, caution when using in other than bottlenose dolphin)

buthorphanol IM- good for bronchoscopy, possible drug reaction with bronchodilators

meperidine IM- with midazolan produces deep sedation (reversible)

tramadol PO- with diazepan produces sedation for tooth extraction

Central intravenous catheters may be placed in the common brachiocephalic vein and hepatic vein (risk of hepatic bleeding, place embolized gelfoam upon removal), both best under ultrason guidance - will allow central venus pressure mesures

Propofol - smooth and reliable anesthesia when in a central vein

Intubation is orally, trachea is short (care not to advance the tube into the separate right accessory bronchus).

maintenance- iso or sevo (better induction and recovery)

use ventilators that allow for an apneustic plateau (prolonged inspiratory hold) for prolonged procedures

Monitor EtCO_2, ECG (normal profund sinus arrhythmia), body temp (rectally to a depth of 15 to 25 cm because of vascular heath exchange system)

Question 7

What are the most common diseases in cetaceans?

Answer 7

Bacterial and parasitic lung infections are the most common in stranded cetaceans and Infectious respiratory is the most common general disease in cetaceans

Question 8

Viral diseases of cetaceans

Answer 8

Morbilivirus (paramixovirus)- debilitation, severe pneumonia, and encephalitis. Mortality in in situ populations of cetaceans worldwide most prevelant in the Atlantic Ocean. PCR.

Question 9

Bacterial diseases of cetaceans

Answer 9

Erysipelothrix (Gram + rod): bac found in mucous layer of feed fish. Blood culture. Vaccine (licensed for swine).

Nocardia (Gram + rod): high mortality - systemic form is more common (involving two or more organs, most frequently lungs and thoracic lymph nodes)

Mycobacterial (differential for Nocardia): Respiratory and cutaneous. Serum antibodies in free-ranging Atlantic bottlenose dolphin. Tuberculosis-causing mycobacteria have not been reported in cetaceans.

Brucella, Bartonella

Antibiotic resistant bac in in-situ bottlenose dolphin: Staphylococcus aureus (MRSA), E.coli, Pseudomonas

Question 10

Fungal diseases of cetaceans

Answer 10

Most commonly lungs, lymph nodes, an dcutaneous abscesses

Dx: radiography, bronchoscopy with BAL, untrasound-guided biopsies or FNA

Aspergillus, Candida, Lacaziosis

Question 11

Parasitic diseases of cetaceans

Answer 11

Toxoplasma gondii: in and ex-situ. When manifests commonly neurologic, but cardiac muscle and systemic manifestation possible. vertical transmission on stranded Risso’s dolphin.

Sarcocystis neurona

Question 12

Noninfectious diseases of cetaceans

Answer 12

Urolithiasis always associated with ammonium urate stones (radiolucent). Prevalent in ex situ bottlenose dolphin. Hypocitraturia (citrate inhibits Ca stone formation) may be predisposing factor. Nephroliths form in the collecting ducts and renal calyx, presenting as chronic hematuria. Azotemia might not manifest for many years. Ultrasound diagnosis has variable efficacy. Two reports of obstructive urolithiasis (market azotemia, hydroureter), only one successful treatment with laser.

Vaginal calculi (struvite) in harbor porpoise

Question 13

Reproduction in cetaceans

Answer 13

Odontocetes have a fibroelastic sigmoid-shaped penis (similar to cattle), testes in the abdomen

Femeals have a bicornate uterus with species-specific series of vaginal and cervical folds or rings (hysteroscopy is challenging)

Placenta is diffuse epitheliochorial (neonate depends on colostrum)

Reproduction might be monitored with urinary hormones and utrasound

estrus synchronization with progestin (usually altresnogest)

Ovulation occurs 20 to 30 days after progestin. Monitor ovulation via LH in urine (min. 3x/day) and single-dose artificial insemination 28 to 35 hours (species dependent) after LH surge. Semen is deposited in the uterus using flexible scope.

Question 14

Pregnancy in cetaceans

Answer 14

pregnancy is long, best diagnosed with ultrasound (as early as 30 days but usually at 50 to 60 days). Serum progesterone levels peak around weeks 9 to 12 following conception. Pregnancy is confirmed by progesterone presistance, not its increase and ultrasound.

synthetic progestin has been used to mantain pregnancy when corpus luteum failed, but all had parturition complications.

hematologic and serum chemistry changes occur in pregnant killer whales (reflect a progressive mild inflammation)

Fetal growing algorithms exist for bottlenose dolphings and fetal omphalocele and anencephaly have been diagnosed with gestational ultrasound.

Fluke-first is the most common presentation, twins are rare. Neonatal Tursiops survivability has increased due to neonatal handling and care practices (weight, blood work 7 days or earlier)

Question 15

Cetacean contraception

Answer 15

Planned separations based on ultrasound and urinary hormons

Altrenogest (progestin) PO, SID may prevent ovulation, but has failed.

luprolide acetate IM every 28 days has been successfully used in male bottlenose dolphin, reducing testosterone and causing azoospermia. Increase testosterone occurs in the first 14 days.

Megestrol acetate (steroidal progestin) is not reliable contraceptive in male dolphins.

Question 16

Anatomy of sirenias

Answer 16

manatees eat aquatic vegetation, including grasses and algae

Dugong has proeminent incisor teeth (both gender)

Each lung consists of an elongated single lobe in its own pleural cavity created by the hemi-diaphragms

Heart is cranioventral to the pleural cavity and separated from abdomen by a transverse septum

hindgut fermenters, with a single C-shaped stomach with a digestive cardiac gland

Cecum is rounded with 2 accessory sacs (rabbit ear apearance

vulva anterior to the anus, distal vagina is vertical. penile opening is near umbilicus.

Sirenias are prone to anxiety, minimize noise and human presence

Question 17

Most common reasons for manatee presentation in rehabilitation centers

Answer 17

cold stress, orphaned calves, watercraft injuries (and other human related etiologies), other natural diseases (reproductive complications, biotoxins, etc)

Question 18

Sirenia anesthesia

Answer 18

Intubation can be acomplished under heavy sedation through the nasal cavity with broncoscope. Trachea is short (less than 10 cm).

Butorphanol with diazepan or detomidine or midazolam

Detomidine (narrow therapeutic index, cardiac and blood pressure effects not noted)

Meperidine (alone or with midazolam)

Midazolam (mild to moderate sedation. Alone or in combinations)

Xylasine (moderate sedation)

Question 19

Sirenia diseases

Answer 19

Neonatal: prematurity, inanition, poor adaptation, watercraft injury, infections (omphalitis), hypoglycemia, dehydration, constipaton, enterocolitis, pneumatosis intestinalis, congenital defects (ectrodactyly of pectoral fliper, atresia ani, omphalocele)

Intoxication: brevetoxin (red tide, Karenia brevis). Neurologic compromise, lethergy, incoordination, seizure. serologic test and water sample. Treatment is preventing drowning. recovery is rapid.

Infectious: Leptospirosis, T. gondii, Cryptosporidium, Papiloma virus, Morbilivirus, Mycobacteria

Watercraft injury: one of the largest reasons for mortality and rescue.

Blunt trauma and pneumothorax: External wounds and asymmetrical buoyancy is highly suggestive of pneumothorax. Radiography. Flotation jackets might be needed in severe cases. Most animals respond to conservative tx (chest tap once a week until resolution). Chest drains have mixed results.

Question 20

Sirenia reproduction

Answer 20

female manatees mature between 3-5 years, dugongs 10. Gestation leght is 12-14 months (manatees), 13 months (dugongs). Calves nurse 1-2 years.

Female manatees without a male may undergo behavioral changes during estrus (spin swimming, isolation, abdominal flexion, inapetance).

Reproductive complications include fetal death, abortion (trauma and handling on last trimester) and dystocia (calf extraction under sedation, cesarean).

Question 21

General biology Pinnipedia

Answer 21

Carnivorous, 3 suborders: odobenidae (walrus), Otoriidae (sea lion and fur seals) and Phocidae (true seals)

In otoriids the thoracic appendages are dominant and animals can “walk”, phocids do not. Phocids are unable to rotate pelvic appendages (hind flippers)

genus Pusa - nich in fresh water, the remainder are marine

Rates of congenital defects in Northen elephant seals are highest, possibly due to defect heritability and lack of genetic diversity

Study in 371 stranded California sea lions found that sick animals have higher-than-normal parental relatedness, suggesting impact by human exploitation

Low major histocompatibility complex allelic diversity was shown to be a strong predictor of pup survival in gray seal (UK)

Pinnipeds are great sentiel species for domoic acid intoxication, leptospirosis, urogenital carcinoma, and malnutrition because they share with humans risk factors for diseases

Question 22

Pinnipedia anatomy/phisiology

Answer 22

The hind flipers incorporate the tarsus, metatarsus and phalanges. The proximal limb bones are incorporated within the trunk

kidneys are discretely multireniculated, composed of multiple functional subunits, presumably an adaptation to life in hypertonic enviroment

all are monogastric with very long small intestines

dentition is polyphydont (continuously replaced) and heterodont (different tooth morphology), deciduous teeth are reabsorbed prior or shortly after birth

all have delayed implantation therefore diagnosis of pregnancy might be difficult early. depot GnRh has induced local reaction.

Question 23

Phocids anatomy

Answer 23

lack external pinnae and the external auditory canal is surrounded by a rich vascular plexus (protects the ear canal and tympanum from diving pressure)

Unilateral hind flipper amputees do well

Thermal insulation is provided by skin and SC adipose stores rather than pelage. skin thickness varies and species variation exits between the amount of lipids incorporated into the skin.

vascular adaptations to diving:

• spinal cord is surronded by extradural vascular sinus, flow is variable, rostral at times and caudal at others.
• Proeminent abdominal venus plexus that drain to a large “hepatic sinus’ and then to the thoracic vena cava.
• muscular sphincter ar diaphragm appers to “meter out” blood as cardiac preload during dive, augmented by sympathetically splenic contractions.
• venous PO₂ might exceed arterial at times as a result of blood shunted to metabolic active tissues
• testes are in the inguinal area, no scrotum

Question 24

Otariids (sea lion and fur seals) anatomy

Answer 24

they have pinnae

Amputation of a pelvic appendage cause no significantly disability, but amputation of foreflipper is not recommended, but arthodesis of carpal joint has been effective

fur seals have a specialized hair coat that traps air for thermoregulation, sea lions do not (they rely primarily on SC fat for insulation).

Sea lions younger than 1 year have a proeminent maxillary corner incisior (confused with canine). During second year the canine erupts.

Carina is located near the level of the thoracic inlet not at the base at the heart like phocids

They posses a proeminent hepatic sinus but abdominal plexus are not as significant as in phocids

Question 25

Obenids (walruses) anatomy

Answer 25

All flippers are important for locomotion, have tusks (often clinical concearn).

rely on adipose whithin modified skin and SC tissue for insulation.

have diverticulae of the oropharynx

More prone to GI obstruction compared with other pinnipeds, since the pyloric outflow of otariids and phocids are small in diameter and walruses apper to ingest anything in a controled environment.

Question 26

pinniped biology/housing

Answer 26

risk of hyperthermia when out of the water (do not restrict access to water)

Emaciated young animals and animals under anesthesia at risk of hipothermia if ambient in cold.

If stable young orphans should be exposed to water following feeding to stimulate GI motility

Protection from solar exposure is significant regarding ocular health. Evidence of keratopathies ans secondary intraocular disease are associated with solar radiation. Captive animals without shade were almost 10 times as likely to develop lens luxation, cataracts or both.

eyes are adapted for low-light visual acuity (forage in water columm some in great depths)

Provide shade, non-reflective surfaces, feeding under water, and attention to water quality are preventative.

study: Eye disease is common in wild (35%) and captive (81.5%), with a higher prevalence in captive populations.

Water quality of marine mammal enclosures is mandated by the Animal Welfare Act and enforced by the Animal and Plant Helth Inspection Service of the US department of agriculture (USDA)

Question 27

Pinnipeds diet

Answer 27

largely piscivorous but can forage crustaceans (walruses) and other invertebrates

supplement diet with thiamine, vit A and E

Proper handling of food fishs with attention to time-temperature profiles (less handling at cold temperatures is optimal)

Elephant seal wealings fast for 4-6 weeks (food and water) following departure of the dam prior to inniciating foraging (no biomarkers to recognize this normal status have been recognized, plasma hormones and fat acid profiles have been investigated). Adult pinnnipeds will go “off feed” during rut behavior.

Adept to metabolic water production via oxidative phosphorylation of fats

Pinniped milk is virtually devoid of carbs. GI disorders can happen in artificially reared neonates (diarrhea, ileus, atony, impaction) and could be related to the addition of carbs in formula. No transitional time between suckling and solids.

Question 28

Pinniped anesthesia

Answer 28

Risk of sufocation due to robust distensible pharyngeal soft tissue that may obstruct the glottis, the optimal position is extension of head and neck with mouth open. Animal have suffocated when folded up against the side.

in otariids cuff should be positioned just beyond teh laryngeal cartilages (otariid carina ia at thoracic inlet)

normal ETCO₂ of 70-80 mmHg are not uncommon

flippers are prone to thermal burns due to direct contact

central venous pressure might be monitored by catheter placement into the jugular or radial artery (mean arterial pressure) with ultrasonographic guidance. Indirect pressure is not accurate.

Most GI foreign bodies don’t pass the gastric pilorous (except in walrus) and can be retrieved endoscopically

dry docking after surgery is possible but not advisable

Question 29

Toxic drugs in pinnipeds

Answer 29

Azole antifungals have been implicated in fatal hepatopathy in sea lion.

extrapiramidal effect of haloperidol when used for chronic regurgitation

vasoactive drugs (phenothiazine, alpha2-agonist) might interfir with physiology associated with hemostasis during diving

Question 30

Toxicoses

Answer 30

Domoic acid: toxin mimics the neurotransmiter glutamate and it is biomagnified up the food web. Acute and chronic forms. Subtle behavioral deficits to epilepsy. Pups exposed in utero have develop seizure latter in life. Hypothalamic-pituitary-adrenal axis may be disrupted. Response to auditory stimuli may be useful as indication of prior intoxication.

Question 31

Noninfectious diseases of pinnipeds

Answer 31

Malnutrition most common reason for rehabilitation

Entanglements or ingestion of human-made debris are common

Intestinal foreign body uncommon, if FB passes the small pyloric sphincter it may pass to the anus (except walrus).

gastric FB are not uncommon, but like cetaceans, pinnipeds may voluntarily induce emesis (can also become abnormal behavior) . Endoscopy indicated.

Neoplasia affects free and captive animals. Urogenital carcinoma causes varying degree of posterior paresis to paralysis and perineal edema. sublumbar lymphadenopathy is often detected early in the course.

Question 32

Most common Pinniped disease

Answer 32

dermatopathies and ocular disease have a high prevalence in collections (likely because of enviromental conditions - water quality and exposure to radiation)

Question 33

Viral diseases of pinnipeds

Answer 33

Calicivirus (ubiquitous to environment): Otariids - varies with strain, from mild GI signs to severe vesicular stomatitis and dermatitis of the glabours skin of the appendages. Abortion and encephalitis have been reported. morbidity is moderate and mortality low. Isolated innculated in swine cause a disease indistinguishable from vesicular exanthema.

Phocine distemper virus: caused epizootics in seals in Europe. anti-morbilliviral Antibodies detected from pinnipeds from Antartic to Canadian Artic. experimental canine distemper infection in phocids.

Phocine herpesvirus (ubiquitous to environment): essentialy all free-ranging seroconvert. Virus associated with outbreaks of CNS or adrenal disease in rehabilitation facilities.

Influenza A virus: epizootics in seals (subtypes H7N7, H4N5, H4N6, H3N3, H3N8). seals are potential intermediary host from avian host to humans, particulary H3N8.

Poxvirus: typical verrucous lesions. common in young animals in rehabilitation.

WestNile and EEE virus infection have been documented in harbor seal.

Question 34

Bacterial diseases of pinnipeds

Answer 34

Leptospirosis: endemical in california sea lions along CA cost, most often L. interrogans pomona (serovar appers unique to sea lion). Acute interstitial nephritis. agressive fluids and antibiotics have resolved cases.

Tuberculosis: recognized in otariid pinnipeds. M. pinnipedii. outbreaks where bac. spread from pinnipeds to Malayan tapir, camels, and porcupines. appears to be absent in north america.

Brucella sp.: clinical significance unknown. Clinical disease less common than cetaceans.

Mycoplasma sp.: soft tissue and joint infections in sea lions, often involves conective tissue of appendages.

Question 35

Fungal disease of pinnipeds

Answer 35

fungal dermatopathy: sea lion in rehabilitation facilities, multi-focal maculae characterized by discrete circular hyperpigmentation and patchy alopecia. Trychophyton has been identified.

Coccidiodes immitis: disseminated infection regularly seen in CA coast. declared select agent by USDA.

Question 36

parasitic disease pinnipeds

Answer 36

susceptible to Toxoplasma, Neospora, Sarcocystis

Verminous pneumonia is wide-spread, well-recognized, debilitating in young animals.

Acanthocheilonema odenhali: common filarid nematode CA sea lion, frequent found in blood of rehabilitation animals. adults live in the fascial planes and subcutis of the neck and axillae, but do not cause disease. microfilaria may be confused with D. immitis.