Veterinary Care

Goatscaping: Eating away a poison ivy nuisance

The guests are gone, the zoo is quiet – now it’s time to get to work. One by one, eight goats make their way into the 19,000-square-foot chimpanzee habitat.

With the chimps safely in their night quarters, the lights are left on for the goats, who’ll work into the morning. Their experimental task: eat all of the poison ivy that’s grown in the chimp and gorilla habitats.

To these nature’s lawnmowers, it’s just another green meal. The plant causes no harm to our primates or the goats, but it makes zookeepers’ jobs increasingly difficult. Preparing the habitats in the morning becomes a game of dodgeball as they try to avoid the toxic plants.

“They’re getting ivy all over their bodies,” said Keith Zdrojewski, mammal curator. “They’re out there wearing long-sleeved shirts and pants to trim the grass in 100-degree weather. It’s pretty cumbersome for everyone.”

The goats mow through the poison ivy with ease. “They’re an incredible species that can survive on a diet that other animals would starve on,” said Dr. Jan Raines, one of the Zoo’s veterinarians. “The compound in ivy that gives people allergic reactions is called urushiol. Goats lack a sensitivity to it. Their gastrointestinal tract is amazingly efficient at pulling every last nutrient out of anything they ingest.”

Zookeeper Ashley Orr’s personal goats are eating up our problem, saving us money by not having to hire a company to kill the ivy. And we’re doing it in an eco-friendly fashion. “This way, we’re eliminating chemicals from entering our animal’s habitats, and they’re leaving behind a clean natural fertilizer for the landscape,” Zdrojewski said.

When the sun rises, they’re back in their holding barn, waiting for the zoo to close again.

The goats enter the chimp habitat with owner and zookeeper, Ashley Orr.
The goats enter the chimp habitat with owner and zookeeper, Ashley Orr.
Dallas Zoo/Cathy Burkey
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Categories: Chimpanzee, Mammals, Nutrition, Veterinary Care, Zookeepers | Tags: , , , , , , , , , | Leave a comment

There’s just no such thing as a ‘typical’ day for zoo vets

On any given day, the Dallas Zoo’s three veterinarians might work on a tiny frog who weighs a few grams and then examine an elephant that weighs 10,000 pounds. That’s the irony of “specializing” in zoo veterinary medicine: one must be a generalist for hundreds of mammal, bird, reptile, fish, and invertebrate species.

Vets must know how to recognize different digestive, vascular, and reproductive systems; infectious and chronic illnesses; pharmacological needs; and animal behaviors in order to develop courses of care.

MEDICATIONS: Administering drugs isn’t simple as picking up a ‘script from Walgreen’s. Zoo vets often have to improvise when calculating drug dosages, because pharmaceutical companies don’t publish formulations for every species. The vets know that a published dosage for a horse would be good for a zebra, or that antibiotics effective on lizards would probably work with snakes. Compounding pharmacies may be used to create concentrated volumes for large-animal needs.

“But you can’t just increase the dosage of some drugs because the animal is bigger,” explained Christopher J. Bonar, V.M.D., Dipl. A.C.Z.M., director of animal health. “Sometimes we have to do metabolic scaling to formulate dosages based on an animal’s metabolic rate. Large animals like rhinos have a slow metabolism.”

SPECIALTY EQUIPMENT: When necessary, veterinarians must be creative with equipment to accommodate everything from tiny poison dart frogs to long-necked giraffes. They’ve turned urinary catheters into endotracheal tubes. Anesthesia masks have been made from pop bottles and construction cones.

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Dr. Maren Connolly examines koala Tekin while he’s under anesthesia as part of his annual checkup. Dallas Zoo/Cathy Burkey

ANESTHESIA: Like with humans, putting an animal “under” and performing surgery are last resorts. That’s why zookeepers train animals to demonstrate behaviors that make it easier to draw blood, administer shots, and conduct exams.

There are a few times when anesthetizing an animal is risky – for the vets! Herpetologists noticed that a red spitting cobra wasn’t eating or defecating, and had a swollen abdomen. The snake had a history of kidney problems, common to this species. The challenge was to sedate the venomous snake.

“Our very skilled snake keepers helped on this one,” Bonar said. The dangerous end of the cobra was drawn into a plastic tube so the vets could pump gas to anesthetize it. “We inserted a tube into the trachea to ventilate it during surgery and confirmed that the snake had a renal tubular carcinoma. After testing the other kidney to make sure it was functioning well, we removed the affected kidney.”

BIRTH DAYS: It’s exciting when babies are born – or hatched. Newborn antelopes and other herd animals are often checked and tagged 48 hours after birth. Although recognizing newborns may seem simple, herd animals often deliver at the same time of year, and the babies look strikingly similar. Vets check the mother’s lactation and the baby’s suckle response and hydration. During difficult labors, vets may manually assist with breech births or perform C-sections.

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Keepers trained Ramona chimp to allow an ultrasound during her pregnancy to check on the fetus. Dallas Zoo/Cathy Burkey

Vets monitor hormone levels or perform ultrasounds for some expectant mothers, such as Marge warthog and Ramona chimpanzee. Both mothers were trained to allow vets or a veterinary ultrasonographer to apply a jelly-like substance to their bellies for the test to check the fetus’s health and estimate due dates. Ramona even learned to hold on to the bars of her bedroom to make the job a little easier. After babies are born, vets usually wait to do well-baby exams until mom is ready to eat away from the baby or share care with others in the group.

Zoo populations often use the same methods as humans to limit or facilitate pregnancies. Many animals are on birth control so the population doesn’t get out of control or inbreeding doesn’t occur. In cases where there is a need to increase the population or genetic diversity of a species in the Association of Zoos & Aquariums (AZA) Species Survival Program (SSP), vets may use assisted reproduction.

“We always prefer natural reproduction,” Bonar said. “Techniques that work with a horse or cow won’t necessarily work with a rhino or cheetah. We work with the SSPs and a company that does hormone analysis and makes reproductive recommendations for us. But basically we watch to see if the females are coming into estrus. Are the males fertile? Are the animals compatible? Sometimes absence makes the heart grow fonder, and we recommend a simple change in environment for a short time.”

Zoos with expertise in breeding certain species often serve as consultants. The Dallas Zoo advises on okapi breeding at other facilities.

Advanced Diagnostics: Bonar and his team of vets routinely test blood or tissue samples, but they often send them to more than a dozen pathology labs, each one specializing in a certain species or test. When an animal passes away; vets perform necropsies to determine the cause of death so that information can contribute to the body of knowledge among scientists and zoo professionals. When possible, tissue and bones are donated for educational purposes.

In the wild, many animals don’t exhibit obvious signs of illness because other members of its group may perceive it as weakness or because the animal may become easy prey. Diagnosing challenging cases may require the services of offsite computed-tomography (CT) or magnetic-resonance imaging (MRI) facilities.

Outside medical specialists allow the hospital team to extend their resources. The Dallas Zoo routinely works with specialists on cases requiring ophthalmic or dental surgery, CT or MRI scans, pathology results, and hoof trims. That’s why the Zoo is assembling a Medical Advisory Committee. The depth of knowledge of the Zoo’s veterinary team, combined with the expertise of several specialists, will help provide even better care.

Categories: Chimpanzee, Elephant, Giraffe, Mammals, Okapi, Reptiles and Amphibians, Veterinary Care | Tags: , , , , , , , , , , , , , , , , , | 2 Comments

Giving 100%: Zoo’s veterinary team is always on duty

The patient was rushed to the hospital, less than a quarter-mile from her home, with a neck injury and a puncture wound to her abdomen.

Unable to communicate, she was quickly anesthetized so the scope of her injuries could be determined. Exploratory surgery revealed no intestinal damage and the deep wound was flushed and cleaned. X-rays identified a slight neck fracture, which was immobilized by an improvised splint, because there was nothing standard to fit her tiny neck. She was given antibiotics and painkillers, and was fed through an intravenous tube until she could eat on her own.

Most of the world’s scavengers don’t get this level of care, but the African white-backed vulture and other animals at the Dallas Zoo have access to four full-time veterinarians, a top-flight hospital, and more than a dozen other professionals who provide care and nutrition.

The $3.75 million A.H. Meadows Animal Health Care Facility sits behind the elephant and gorilla habitats in the Wilds of Africa. The hospital, as well as other areas of the Zoo that involve animals and zookeepers, are overseen by Lynn Kramer, D.V.M., vice president of animal operations and welfare. A veterinarian, Kramer follows the progress of animals treated by the hospital staff and consults on special cases.

“This hospital is one of the best,” Kramer said. “It ranks in the top 10 percent of zoo hospitals around the country – and I’ve seen most of them.”

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Dallas Zoo veterinarians put koala Tekin under anesthesia to perform an annual checkup on him recently. He got a clean bill of health. Dallas Zoo/Cathy Burkey

Day-to-day care is led by Christopher J. Bonar, V.M.D., Dipl. A.C.Z.M., director of animal health, who came to the Dallas Zoo and Children’s Aquarium at Fair Park in January 2013. Bonar is involved in all aspects of clinical medicine, surgery, diagnostic imaging, pathology and nutrition, as well as reviews of preventive medicine, quarantine, and anesthesia protocols. He oversees three full-time veterinarians as well as vet technicians, hospital keepers, a hospital record administrator, a certified nutritionist, and the Animal Nutrition Center and nutrition team. And he’s responsible for developing research and publication goals for the department.

Bonar was planning to become a doctor when he attended Harvard University for his undergraduate and master’s degrees in biology, and expected to support his love of zoos and aquariums through philanthropy. But with his father’s encouragement, Bonar followed his passion, graduated from the University of Pennsylvania’s School of Veterinary Medicine, and became part of a select group of zoo veterinarians who have earned board certification from the American College of Zoological Medicine. He works with Jan Raines, D.V.M., and Maren Connolly, D.V.M., to care for more than 2,100 animals (not including invertebrates).

The team makes it a point to keep their calendars clear for a portion of every day to accommodate emergencies, and someone is on duty or on call 24 hours each day. Most of their time is filled with well-patient care: administering tuberculosis tests, performing chest X-rays, updating vaccines, and conducting dental and ophthalmic exams.

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X-ray of a Thompson’s gazelle.

Incoming animals, which are quarantined for 30 to 45 days, get physicals and X-rays, and are checked for parasites and viruses. Vets also examine outgoing animals to ensure that they are free of contagious diseases before they leave Dallas.

The veterinarians talk with curators and zookeepers about any unusual animal behavior that may warrant further investigation. For example, if an animal has started limping or is lame, vets may prescribe an anti-inflammatory drug (for minor cases) or may immobilize an animal to treat more serious issues.

Recently, the Dallas Zoo team monitored the health of an Aldabra tortoise for almost a year, because it wasn’t eating as much as it had in the past. Keepers and vets couldn’t find an obvious problem, and its large shell and the arrangement of tortoises’ internal organs made ultrasounds, x-rays, and laparoscopic tests ineffective. So the tortoise was taken for a CT scan. Tests revealed a tongue lesion that was repaired with a laser supplied by another veterinary specialist. The tortoise is now eating well.

“Here’s an animal that was 15 years old, but has a very long, long life ahead of him,” Bonar said, referring to the 150-year life span of Aldabra tortoises.

In another instance, the carnivore keepers at Giants of the Savanna noticed that Bonde cheetah wasn’t eating as usual, and they were concerned that he had ingested a foreign object. Raines studied blood and fecal samples and examined the cheetah with an endoscope. When Bonde hadn’t eaten 48 hours later, she administered a barium radiograph and identified an intestinal adhesion, which would have been fatal if not treated. Raines removed the problem, and the cheetah was up and running days later.

The health care and well-being of animals at the Dallas Zoo and the Children’s Aquarium are the primary focus of everyone associated with the A.H. Meadows Animal Health Care Facility, the ANC, and an entire team of zookeepers, staff, volunteers, and supporters. It’s likely that Aldabra tortoise will outlive all of us – and that’s the goal of this team.

Categories: Birds, Cheetah, Koala, Mammals, Reptiles and Amphibians, Veterinary Care | Tags: , , , , , , , , , , , , , , , , , | Leave a comment

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