1.1. Learning Objectives

• Be familiar with the federal regulations and agencies governing work with wild or captive marine mammals
• Gain an appreciation for the common safety and health issues involved in capture and restraint of marine mammals
• Be familiar with the common health issues related to captive husbandry of marine mammals
• Understand the significance of emerging morbilliviruses in marine mammals

1.2. Anatomy Review

Please review the marine mammals information in your 1st Year Comparative anatomy syllabus before attending this lecture. Additional information can be obtained from the texts listed at the end of the chapter and also may be viewed at

Anatomy of Cetaceans

2.1. Taxonomy

2.2. Laws Governing Acquisition And Care Of Marine Mammals

• Marine Mammal Protection Act
  • Passed in 1972; last updated in 1994
  • Protects and promotes growth of marine mammal populations and their resources
  • Allows exemptions by permit in some cases
  • Clarifies roles of NMFS and FWS as they pertain to marine mammals
  • Regulates animal transports
• Animal Welfare Act
  • Passed in 1966; last updated in 1990
  • Regulated by the USDA APHIS
  • Ensures that animals used in research, public exhibits, or as pets are provided with humane care and treatment, and provides transport standards for these animals
• Endangered Species Act
  • Passed in 1973; last updated in 1988
  • Permits allow taking of listed animals for research, propagation, native subsistence
  • Enforcement of violations includes fines and jail terms
• Convention On The International Trade in Endangered Species
  • Included in the Endangered Species Act
  • Established in 1973
  • 150 countries participate in this agreement
  • Trade of listed species is regulated or prohibited

2.3. Bodies With Regulatory Or Advisory Jurisdiction Over Institutions Maintaining Captive Held Or Stranded Marine Mammals

Regulatory bodies are empowered to make unannounced inspections of facilities and husbandry and medical records.

• National Marine Fisheries Service NMFS (NOAA Fisheries)
  • Supports fisheries management and development, and enforcement of guidelines
  • Protects species through habitat conservation
  • The official regulatory authority for cetaceans and pinnipeds, except walruses
• U.S. Fish and Wildlife Service
  • The principal agency for conserving, protecting and enhancing fish, wildlife, and plants and their habitats
  • The official management authority for sea otters, polar bears, walruses, manatees/dugongs and sea turtles
• Animal Plant Health Inspection Service of the USDA
  • Regulates the treatment of marine mammals held in captivity
  • Determines health standards, including space requirements, water quality standards
  • Implements all facets of the Animal Welfare Act
  • Makes unannounced inspections of facilities to inspect facilities, and husbandry/medical records
• The Marine Mammal Commission
  • Established under the Marine Mammal Protection Act
  • Responsible for developing, reviewing, and making recommendations on policies of federal agencies with respect to marine mammal conservation and research
  • Independent agency of the US Executive Branch consisting of 3 commissioners appointed by the President
• State Veterinary Regulatory Boards
  • Most state veterinary boards will not take jurisdiction over facilities maintaining marine mammals
  • Generally, states comply with all aspects of federal jurisdiction and leave regulation of such facilities to the USDA APHIS team.
  • May waive state license requirements for veterinarians working solely in such facilities
• Institutional Animal Care And Use Committee
  • APHIS-required committee that oversees the care and use of collection/stranded animals used in a research setting
  • Oversees and modifies as necessary all research projects to ensure that animals are used appropriately in regards to pain and discomfort
  • Oversees the institutional facilities in which animals are housed

3.1. Thermoregulation

Heat transfer ability of water is 25X more efficient than air. Adaptations associated with thermoregulation:

• Large size - there are NO small marine mammals
• Body shape to minimize surface area
• Body insulation - blubber, dense fur
• Arteriovenous anastomoses (AVAs) - alternate blood return route that closes when there is a need to conserve heat
• Counter-current heat exchange - periarticular venous rete
• Behavioral

3.2. Pressure and Diving

Pressure increases 1 atm/ 10 meters depth - a dolphin diving 1000 feet is at a pressure 100X greater than it was at the surface

3.3. Osmotic Regulation

• Seawater is hyperosmotic to the mammalian body so there are physiologic demands of water intake, retention and elimination
• Water production
  • Virtually no direct water intake except with pinnepeds - no access to fresh water
  • Metabolically-produced water via oxidation of proteins and fats
  • Inspired air is a potential source if there is sufficient gradient at the alveolar/capillary interface

3.4. Reproduction

• All reproductive organs are internal.
• Cetacean placenta is epitheliochorial to result in the least amount of blood lost in parturition
• Cetacean parturition is normally breech presentation ensuring the umbilical cord remains intact for the longest duration possible.
• Delayed implantation, or embryonic diapause, in pinnipeds and sea otters
  • 3-5 months
  • To align fetal development with the season of highest reproductive success.

3.5. Cetaceans

• Large lungs, thorax very flexible and collapsible at depth
• Blowhole, energy saving means of respiring, also involved with sound production
• Larynx is detachable from cranial recess for intubation purposes
• Cartilaginous bronchioles to level of tertiary bronchioles, allows rapid flow of inspired air
• Vascular retes, involved in countercurrent heat exchange thermoregulation and supplying oxygenated blood preferentially to certain organs during dives
• Multicompartmened stomach, enlargement of the first compartment permits gorge feeding in "times of plenty".
• Polyreniculated kidneys
• Blubber, prevents heat loss and provides hydrodynamic faring
• Absence of hind limbs
• Presence of a large brain with extensive enhancement of portion of cerebral cortex involved in auditory processing
• Ability to survive without sources of fresh water except water of metabolism
• High PCV, large RBCs and high myoglobin levels combine with dive reflex and thoracic rete to permit extended breath holding periods
• Presence of flukes and dorsal fin, aid in thermoregulation and locomotion
• Spherical lens aids in visual accommodation in air and water

Viscera of a cetacean

3.6. Pinnipeds

• Large caval sinuses can act as a storehouse of oxygenated blood
• Thick blubber layer to prevent heat loss, very dense fur in pinniped species lacking a thick blubber layer
• Cartilaginous bronchioles aid in rapid movement of inspired air
• Webbed hind flippers
• Polyreniculated kidneys
• Spherical lens aids in visual accommodation in air and water
• High PCV (large and numerous RBCs)
• Pronounced dive reflex
• Large lung capacity

Viscera of a pinniped

4.1. Space

The size of a marine mammal enclosure is regulated based on the size and behavior of the species being maintained. Important factors include; minimum horizontal dimensions, water depth, and in the case of pinnipeds, dry resting area.

4.2. Environmental Quality Issues

These involve the physical features of the air and water and any added compounds.

4.2.1. Air Quality:

The principal concern is related to indoor exhibits or holding areas which must maintain a continuous supply of air with adequate exchange rates to prevent the development of excessive odors, chlorine or ozone breakdown products or gaseous breakdown products of animal metabolism.

4.3. Marine Mammal Housing

• Most cetaceans are dependent upon salt-water environments.
• 3 Main categories of water systems
  • Closed - recirculated seawater
  • Semi-Closed - enclosed water mixed with new
  • Open - natural seawater constantly circulating
• Trade-off: Vigilant water quality maintenance of closed systems versus exposure to natural threats (ex. pathogens, contaminants etc) of open systems

4.3.1. Cetacean Requirements

• Seawater!!! - cetaceans housed in <15 ppt salt will develop dermal changes and electrolyte disturbances.
• Facility Design Considerations
  • Outdoor vs. indoor
  • Tanks vs. net pens vs. open ocean with barrier
  • Slide-out/beaching area
  • Shallow underwater rim along perimeter
  • Numerous pools for animal separation
  • False bottom
• Every facility should have the means to safely and easily access animals in and out of the water.

4.3.2. Pinniped Requirements

• Need access to both fresh and salt water
  • Pinnipeds kept in freshwater commonly develop ocular problems such as corneal edema, cataracts and eventually chronic keratopathy
  • Pinnipeds (esp. phocids) may been reported to develop electrolyte disturbances and an AddisonÂ?s-like syndrome if they have no access to salt
• A haul-out area must be provided
• Water access must always be possible - can use a fresh water spout for drinking

4.4. Nutrition

• Feed types: Providing fresh fish in the quantities required by major aquariums and oceanariums is a practical impossibility so freshly thawed frozen fish is normally employed. Ideally several species of fish are available and offered so that animals do not develop a fixation on a single species. This is especially important, as all species of food fish are not always readily available. Invertebrates, especially squid are also regularly included in the diet of captive marine mammals.
• Restaurant sanitation principles should be employed and food should be fit for human consumption : USDA APHIS' - Handling Fish Fed to Fish-Eating Animals
• Veterinarians are involved in the inspection of new lots of fish provided by brokers and should meet with and help educate staff on what constitutes acceptable food fish. Proximate analysis of representative samples of each new lot of food fish should be conducted so that adjustments in the amount fed can be made in order to provide the desired caloric intake.
  • Caloric density of fish varies widely by species, season, catch location etc. so proximate analysis is generally necessary.
  • Caloric density by species (general): Mackerel>Herring>Smelt>Capelin>Squid
• Food preparation practices differ between institutions but should be directed at thawing fish so that the product fed has been thawed for < 24 hrs and its temperature has never exceeded 5C, and that valuable nutrients have not been lost via extensive water thawing.
• Food must be kept at <40°F from catch until feeding
• Vitamin supplementation practices vary but vitamins B₁ (2-5 mg/kcal/day and E (50-100 IU/kg food) are almost universally supplemented.
• Supplementation needs increase in a gestating/lactating female.
• Iron storage disease is emerging as a problem in aged animals of some species so iron and vitamin C supplements should not be used.
• Commercial marine mammals multivitains available from Mazuri.

5.1. Behavioral Restraint

This is the ideal situation in that use of force or drugs is not required. Blood samples are less likely to show a stress leukogram and most procedures are rapidly completed. Unfortunately, training animals to perform husbandry behaviors is very time consuming and, in addition, ill animals are less likely to perform such behaviors. Despite these limitations the number of marine mammals trained to perform husbandry behaviors continues to grow.

• Examples: blood collection, tooth scaling, behavioral injections, maintaining layout

Using behavioral restraint to obtain a blood sample.

5.2. Manual Restraint:

• Experienced staff can safely manually restrain most small pinnipeds (<50kg).

• Manual restraint in cetaceans
  • Place in sternal recumbency, with tucked flippers.
  • People are positioned close to animal on each side.
  • Do not restrict chest expansion
  • Control the flukes!
  • Keep wet for cooling purposes

5.3. Mechanical Restraint:

Large or aggressive marine mammals may require the use of equipment to provide safe restraint. Squeeze cages, dog houses, safety boards, stretchers or snares and nooses are only a few of the mechanical methods designed to level the playing field for individuals handling marine mammals.

5.4. Chemical Restraint:

This category encompasses everything in the range between mild sedation and surgical anesthesia. Marine mammals may present many challenges to safe chemical restraint including thermoregulatory disruption, pronounced dive reflexes and apneustic respiratory patterns and loss of respiratory drive (cetaceans). General anesthesia of marine mammals entails significant risks as compared with a typical small animal anesthetic event. For this reason many marine mammal practioners prefer to employ sedation vs. a surgical plane of anesthesia when the situation allows this option.

• Short acting and reversible agents are preferred.
• Benzodiazapines such as diazepam and midazolam have been safely administered to many cetaceans and pinnipeds without significant adverse effects except a decreased respiratory drive. Doxapram ordinarily will correct this condition.
• Local anesthesia combined with benzodiazepine restraint should prove adequate for the vast majority of minor surgical procedures.

• Opiates provide another reversible option but paradoxical reactions have been reported when these are used in some species of otariid pinnipeds.
• Acycloalkylamines and phenothiazines can depress respiration and depress thermoregulatory centers

6.1. Routine Health Monitoring

• Body weight
  • Trends in weight are clues to overall health
  • Affected by stage of growth, gestation, lactation, season, water temperature, disease
  • Blubber and subcutaneous adipose measurement may be an alternative.
• Regular veterinary inspection is necessary even in the face of apparently perfect health. Marine mammals have the ability to mask significant pathologic changes, as compromised animals in the wild are at increased risk of predation.
• Hematology and serum chemistry analyses
• Fecal flotation
• Nasal/blowhole/gastric/anal/ vaginal/preputial cytology +/- culture
• Body condition assessment
• Ophthalmic and oral examinations
• Palpation, when possible
• Radiographs or ultrasound as indicated

Obtaining a microbiological sample for culture from the blow hole in a Beluga Whale.

6.2. Signs of Illness

• Poor appetite may be the only sign of illness, but also does not necessarily mean the animal is ill
• Unusual behavior
• Weight Loss
• Skin Damage may indicate or lead to serious disease
• Foul breath Vomiting/Diarrhea/Discharges/Urine cloudiness or discoloration

Performing a physical exam on a harbor seal pup.

6.3. Physical Examination

• A thorough history should precede any exam and should include: species, age, condition, temperament, facilities, personnel, specifics of complaint, etc.
• Follow a standard routine, be complete and QUICK
• Usually collect blood first to avoid stress leukogram component
• Need to be able to recognize normal behavior, attitude and appearance
• Observe animal before any "hands-on" exam
  • Body condition, character of respiration, feces
  • Normal behavior?
• Ensure adequate restraint for the safety of the animal and the people.

6.3.1. Ophthalmic Exam

• Normal tear film is viscous and clear
• Sick cetaceans will often have dull, squinting eyes
• Sea lions have a flat central area to their cornea
• Iris hypochromia is common in some species of pinnipeds

Bilateral ocular disease in a harbor seal.

6.3.2. Oral Exam

• Look for fractured, missing, worn teeth
• Tooth condition can help you age stranded animals
• Captive sea lion's teeth are normally stained a dark blackish brown
• Sea lion tonsils may be highly visible normally
• Nasal discharge in pinnipeds may be caused by URI or mites

Routine dental care in Beluga Whale.

6.4. Blood Collection

• Cetaceans
  • Fluke vessels
  • Caudal peduncular vascular plexus
  • Less commonly, vessels in dorsal fin or pectoral flippers
  • Arteries are often generally surrounded by venous spaces so true arterial or venous samples are difficult to obtain
• Pinnipeds
  • Otariids- caudal gluteal veinrun along sacrum off the midline ridge 1/3 of the way from the tuber coxae to base of tail. Also interdigital vein
  • Phocids- To access lumbar extradural sinus, insert needle into an intervertebral space perpendicular to spine, just off midline. Also can use the plantar venous plexus.

6.5. Imaging

• Ultrasound
  • Preferable to radiographs for abdominal information and in large animals
  • Routine part of health evaluation
• Radiography
  • Most useful in smaller marine mammals
  • Best assessment of bone abnormalities
  • Can do contrast studies in marine mammals as well.

Radiology in a Beluga Whale

Ultrasound in the pool.

6.6. Endoscopy

Most common uses are for exmination of the esophagus, forestomach, upper respiratory tract, foreign body removal and artificial insemination.

6.7. Clinical Pathology

Routine bloodwork is a sensitive, not specific, indicator of disturbances in homeostasis. "Normal" values vary by individual and species; also by laboratory and technician. It is important to interpret the entire animal and it's clinical picture, not just the bloodwork. Often times, trends are more valuable than individual values.

7.1. Viral Diseases

• Pox and Papilloma Viruses
• Morbilliviruses
• Herpesvirus
• Caliciviruses

The US Navy is currently testing a DNA vaccine against morbillivirus infection in bottlenose dolphins. A number of institutions vaccinate pinnipeds against rabies with the development of presumably protective titers.

7.2. Bacterial Diseases

Bacterial diseases are often opportunistic invaders accompanying parasitic, viral, or traumatic disease. They are the leading cause of death in marine mammals

• Erysipelothrix
• Leptospira
• Pseudomonas
• Helicobacter
• Mycobacteria
• Brucella
• Nocardia
• Staph and Streptococcus

Vaccination protocols for protection against eryispelas, maleoidosis and leptospirosis are now in place at many institutions. Development of vaccines effective in preventing brucellosis and helicobacter infections are under consideration

7.3. Fungal Diseases

Most are single reported cases often associated with outbreaks of primary disease. An animal that is malnourished, ill, on prolonged antibiotic therapy, or is immunosuppressed will be predisposed to fungal disease.

• Candida
• Fusarium
• Loboa
• Coccidioides
• Aspergillus

8.1. Readings

8.2. Websites

The Animal Welfare Act

The Convention On The International Transport Of Endangered Species

The Endangered Species Act

International Association for Aquatic Animal Medicine (IAAAM) http://www.iaaam.org/

The Marine Mammal Protection Act Marine Mammal Protection Act

Mystic Aquarium http://www.mysticaquarium.org/

National Oceanographic and Atmospheric Administration NOAA http://www.noaa.gov/

National Marine Fisheries Service NMFS http://www.nmfs.noaa.gov/

New England Aquarium http://www.neaq.org/

North Atlantic Marine Mammal Commission http://www.nammco.no/