The Picture of Health
It Takes More Than an Apple a Day to Keep the Zoo’s 2,000 Animals Healthy
The veterinarians at the National Zoo’s animal hospital have their work cut out for them. To be effective, they have to be familiar with the physiology of hundreds of different animals, from kori bustards to coral and elephants to elephant shrews.
“We work with all kinds of wildlife—reptiles, birds, mammals, amphibians, invertebrates, and fish,” says National Zoo Chief Veterinarian Suzan Murray. “And that’s part of the fun and challenge of what we do. It’s the diversity that draws people to this line of work.”
Now You See It, Now You Don’t
The more veterinarians work with the animals in the Zoo’s collection, the more they learn about the different species’ needs. Take for example the two-toed sloth that lives in the Amazonia exhibit. When the animal was due for a physical exam a couple of years ago, Zoo vets got a puzzling picture of his insides.
After they examined the sloth’s abdomen, the vets knew something wasn’t right. It was enlarged and tight. They proceeded to take radiographs and their suspicions were correct. The radiographs showed that the abdomen was occupied by a large round structure—which appeared to be fluid or soft tissue. The vets feared for the worse.
The follow-up exam included more radiographs and an ultrasound. But this time something was different; the sloth’s abdomen no longer felt distended. Plus, no large mass appeared in the radiographs. Using ultrasound technology, they learned that what they saw was actually an enlarged bladder, filled with a substantial amount of urine that had since been emptied. Nothing was wrong after all. Because sloths only descend from trees once a week at most,
they often hold their urine—sometimes even around seventeen ounces—for up to five days!
All in a Day’s Work
It’s not easy to care for the Zoo’s 400 species. But somehow, National Zoo veterinarians pull it off seamlessly. Of course, the job comes with challenges—one of which is working with “patients” that mask their illnesses until they are very sick. Most animals hide their ailments from predators and fellow members of their species so they don’t appear weak.
To make sure the animals in the Zoo’s collection remain healthy, the vets practice preventative health management. “It is much easier to prevent an illness than treat it,” says National Zoo associate veterinarian Nancy Boedeker. “That’s why we implement preventative procedures such as routine examinations, vaccinations, dewormings, parasite screenings, and the quarantine of new animals to the Zoo.”
Despite prevention, some animals still get sick. When there is a problem, Zoo vets respond as soon as possible and can treat any medical problem in any species—from minor ailments to serious life-threatening conditions.
Essential Animal Keepers
Along with preventative practices, the vets rely on keepers to help them identify animals with illnesses. Because keepers work with the animals every day and know them individually, they play an essential role in the healthcare process and can detect subtleties in the animals’ behavior.
What tips them off? Any behavior that is out of the ordinary, like a flamingo that usually socializes in the middle of the flock, but on a given day remains outside of the group. Or a gibbon that always wakes up and immediately wants breakfast, but isn’t hungry on a particular morning. Or a seal that likes to nap in the sunlight, but on a certain day won’t. All these behaviors may look normal to the average zoogoer, but the animal’s keeper recognizes right away that something may be wrong.
Keepers also train the animals to work with the vets. They teach giant pandas to extend their arms while they’re having blood drawn. Down in Beaver Valley, the Zoo’s marine mammals are trained to sit still to receive eye drops or have their teeth brushed.
“It’s amazing to see a 10,000-pound elephant like Shanthi obey a 100-pound woman like [her keeper] Marie Galloway,” says Murray. “But if Marie tells her to put her head down for whatever reason, Shanthi listens.”
The vets also work with the keepers to become more of a friendly face to the animals. Many primates, such as gorillas, recognize the vets who administer vaccinations and may develop an aversion to them. “To promote a positive relationship with the animals that see us as ‘the ones who give the shots,’ we’ll give them treats when it’s appropriate,” says Boedeker. “And occasionally we’ll hang around their enclosures on nontreatment days to become a
familiar face.”
They Get That, Too?
Many Zoo visitors are surprised to learn that a number of animals can contract the same illnesses they do. Some invertebrates, such as the cuttlefish, may develop cataracts. Large animals like giraffes and bears can get arthritis. Ferrets and humans can pass the flu to each other. And any species can get a cancer of any type.
But that’s not all. Tamarin monkeys and toucans can develop diabetes. Gorillas are prone to cardiac disease and many primates come down with colds. And animals like maned wolves and Asian small-clawed otters sometimes suffer from kidney stones.
A Team Approach
Together with clinical vets, veterinary pathologists and nutritionists help meet the needs of the animals in the Zoo’s collection. Additional off-site specialists, such as cardiologists, ophthalmologists, dentists, and surgeons are consulted on a regular basis to help treat specialized problems and challenging cases.
“We have a whole team working to keep the animals happy and healthy,” says Murray. “And each department brings an incredible range of talent to the table.”
Within a living collection, animals occasionally die. After an animal passes away, pathologists conduct a complete necropsy (animal autopsy) to confirm cause of death, identify any incidental abnormalities, and add to the Zoo’s basic knowledge of anatomy. Wild animals such as squirrels, birds, and raccoons that die on Zoo grounds are also examined for diseases like rabies and West Nile virus. These procedures include the microscopic observation of tissues and special testing for infections.
Training the Next Generation
A leader in training zoo medicine specialists, the National Zoo has run several national and international zoo medicine training programs at pre-doctoral and postdoctoral levels for more than 20 years. Zoo vets conduct formal programs for veterinarians in Mexico, Central America, South America, Asia, and Africa. They also invite foreign vets to spend around eight weeks training onsite at the Zoo.
Conservation Research
National Zoo vets participate in many clinical and conservation research projects at local, national, and international levels. Members of a number of professional associations, they publish their research in major veterinary medical journals and present it at national conferences.
Frequently, Zoo veterinarians help develop ground-breaking veterinary techniques, many of which are applicable to the study of free ranging wildlife. “The National Zoo has a research arm that is always looking for innovative ways to care for animals,” says Murray. “Some of the projects we are working on right now include a new way to anesthetize cheetahs, appropriate dosaging for a new duck antibiotic, and the early diagnosis of cardiac disease in gorillas.”
If you’d like more information about animal medicine at the Zoo, go to www.fonz.org/zoomedicine.htm. The next time you visit the Zoo, think about how amazing it would be to work around playful otters, majestic Asian elephants, and feathery flamingos. And remember, there is a lot going on behind the scenes to keep the lemurs, clouded leopards, and komodo dragon in top shape. Even a sloth that only urinates once a week.
