Zoo Medicine Making ‘Truly Remarkable Progress’ : Animal, Human Doctors Learn Working Hand-in-Paw

They brought in the bear at lunchtime.

Curious hospital technicians peeked around corners as zoo keepers gently prepared the sedated, teddy bear-size lesser panda for a CAT scan during the only time of day human patients weren’t scheduled to use the Philadelphia hospital’s expensive equipment.

Neurosurgeons were studying the results intently. The three-dimensional image produced by the sophisticated X-ray and computer assembly showed no signs of abnormality in the fist-size brain of the furry red beast.

“Everyone was extremely cooperative,” said veterinarian Keith C. Hinshaw, director of animal health at the Philadelphia Zoological Gardens. “They always are. We’ve used CAT scans at the University of Pennsylvania Hospital a number of times for our animals.”

The cooperation among medical doctors and zoo veterinarians in Philadelphia is not unusual, according to zoo vets nationwide. In fact, they say, it is indicative of the advancements that have changed their profession in the last decade.

Doctoring exotic animals used to be a hit-or-miss proposition, but zoo vets now have an extensive store of knowledge on even the most obscure species. New drugs have given them the ability to anesthetize animals easily and perform surgery never before thought possible. Zoo vets say that they operate 10 times more often than they did 10 years ago.

Consult With Physicians

Advances in human medicine have also benefited zoo vets. They frequently call on cardiologists, pediatricians, obstetricians, surgeons and dentists for advice and have access to new, sophisticated diagnostic tools such as ultrasound and magnetic-resonance images.

They treat animals with the same drugs used for humans. They put them on reducing diets and give them contraceptives.

As a result, the vets are spending more and more time on geriatrics as their charges live up to a third longer than previously could be expected.

“I’d say it’s been truly remarkable progress,” said Emil P. Dolensek, chief veterinarian at the Bronx Zoo, who started as the park’s only vet in 1969 and who now heads a staff of five. “We used to have to rely on reports of domestic animals--’Well, if it’s safe in a cow it must be safe for an antelope.’ Now it’s rare that we don’t know what we’re doing.”

Dolensek, wearing mechanics’ overalls that did not conceal muscular arms, took a group of veterinary students on a tour of the Bronx Zoo’s brand-new medical center.

The mammoth operating room is equipped with the latest diagnostic machines, well-stocked cabinets and a five-ton hook hanging from a pulley on the ceiling.

Sometimes the most difficult part of an operation is getting the patient onto the operating table, Dolensek said. His staff recently performed minor gall bladder surgery on a walrus.

Unwieldy Walrus Hoisted

“What is a walrus?” Dolensek asked, pausing to wax philosophic. “It is an 850-pound bag of blubber with no handles.”

Next to the operating room is the hospital ward, a row of steel cages containing bare branches or shallow pools--whatever makes the occupant comfortable. The only patient that day, a porcupine with an upset stomach, sat in misery under a heat lamp. Next to his cage, shelves held syringes, cotton gauze and a shovel.

The largest room in the multimillion-dollar medical center is the morgue. It has garage-type doors leading to the outside and another five-ton hook over a steel table.

Every year, 15% of the Bronx Zoo’s 4,260 animals will die of old age, disease or, occasionally, wounds. Each carcass is brought into this room, either whole or in pieces, to be dissected and studied.

The vital organs are placed in jars and samples of tissues are preserved and kept in a sort of lending library.

It is this gruesome procedure, performed now for decades, that has revolutionized zoo medicine, Dolensek said. Zoos all over the country contribute to this vast store of knowledge, which enables vets to track diseases and distinguish healthy tissue for almost every animal in captivity.

“This is the most important, this bank of knowledge,” Dolensek explained, indicating specimens in jars of murky liquid. “This is how we know what’s normal and what’s not.”

It is all a far cry from the Bronx Zoo’s first written medical records. In 1902, Dr. W. Reid Blair recorded that a siamang gibbon seemed listless and depressed, so he prescribed 1 1/2 ounces of blackberry brandy twice daily. The next morning the gibbon was dead.

“Don’t think it will be possible to keep this species in captivity,” Blair wrote of an animal group that is now thriving at the same zoo.

Safe Dosages

The records are not the only major advancement in zoo medicine in the last 10 years. A combination of new drugs and excellent instructions on the exact dosage for each species has made it possible to anesthetize animals quickly and safely, zoo veterinarians said. At one time, anesthetizing an animal meant risking its life.

“The profession has really changed in the last decade, with these new immobilizing drugs,” said Wilbur P. Amand, veterinarian at the Philadelphia Zoo. “It’s a lot better than eyeballing them from 100 feet and taking your best shot, which is what we used to do.”

Zoo vets operate to remove tumors, abscesses and gallstones, and to set bones broken from run-ins with fences or competing animals. But the veterinarians said they stop short of major surgery, such as kidney transplants or heart-bypass operations.

“You do these things in humans because human life is priceless,” Dolensek said. “An animal is not. There has to be a point where you say, ‘We’ve done enough.’ ”

In fact, most zoo veterinarians say their job consists mainly of preventive medicine and animal maintenance, just as it did in the 1950s, when American zoos had only part-time vets and no medical facilities.

They study diet and nutrition, the proper environments and disease control. And they work long and hard in the field of reproduction, which most vets consider to be the single most important aspect of the job.

“There are so many endangered species today, we have to rely more and more on our own animals to replenish our stock,” said Morton Silverman, executive director of the American Assn. of Zoo Veterinarians, founded in the 1960s by the six full-time zoo vets in the United States. Now, there are almost 60 veterinarians who practice full time.

Morton said that although advances in human medicine have helped zoo veterinarians, reproduction is the one area in which the tables are turned. Zoo vets were performing artificial insemination and in vitro fertilizations long before the techniques were available to humans.

“These things go both ways,” says Phil Robinson, chief vet at the San Diego Zoo for 14 years. “Oftentimes, techniques created by vets can benefit the medical community, as well as vice versa.”

On the wall of the Bronx Zoo medical center is an awkward family portrait. The mother is a gentle, wide-eyed Holstein and her calf is a burly, black gaur--one of an east Indian species of cattle.

Flossie the cow, who came from a Wisconsin dairy, was the first animal to undergo in vitro fertilization from a different species and carry the offspring to term.

“She’s an expert embryo carrier,” said Dolensek, patting Flossie’s flank.

In zoos across the country, veterinarians stock up on frozen semen and attempt to fertilize their most prized specimens. Their successes have produced adorable young animals featured in newspapers and given names by schoolchildren.

The reproductive efforts are not always so successful. Ling Ling and Hsing Hsing, the giant pandas at the National Zoo in Washington, have failed to reproduce from any of several matings supplemented with panda semen imported from London.

“Pandas, what pandas?” asked a weary Mitchell Bush, chief veterinarian of the National Zoo.

“I don’t see any pandas here.”

Unlike the doctors of infertile humans, who need to look just for physical problems, zoo vets with infertile patients must look at environment and behavior as well. Often they turn to animal behaviorists who study the species in the wild for clues.

For instance, zoos had trouble getting lions to mate until it was discovered that male lions almost never mate with female lions they are familiar with--perhaps nature’s way of ensuring fresh blood lines.

As a result, zoos separated some lions at birth and later brought them together for mating.

Since too much interbreeding can produce sickly offspring, zoos also cooperate by loaning out animals and semen. At the Bronx Zoo, the semen of some animals is frozen for several generations to vary the genetic pool of the species.

On the other hand, some animals in captivity, such as some types of cats, rodents and hoofed stock, reproduce too often. These animals are neutered or, if vets want to breed them later, the females are put on birth control. Patches placed under the skin dispense a steady dose of hormones, the vets said.

This is another example of zoo medicine outdistancing that of humans. Medical doctors are working to perfect a similar contraceptive for women.

The mortality rate of zoo babies has fallen in recent years, veterinarians said, thanks mostly to obstetrics and diagnostic equipment that allows them to monitor fetal development.

An obstetrician from Thomas Jefferson Hospital was asked to bring ultrasound equipment to the Philadelphia Zoo. Not an unusual request, but this expectant mother was a surly Indian rhinoceros.

“It wasn’t easy,” Hinshaw said.

The rhino was caged while the medical doctor and expensive ultrasound equipment remained safely on the outside. The rhino’s keeper offered bamboo shoots to keep her quiet, then passed the monitoring device over her abdomen as the doctor shouted instructions.

“Unfortunately, a rhino is a lot thicker than a woman,” Hinshaw said. “By the time the sound waves passed through her hide and blubber, it was a good six inches to the fetus and we could barely visualize anything--just an occasional hoof going by.”

Mother, Baby Fine

The rhino produced a healthy female calf a few months later, Hinshaw said.

“The doctor got a real kick out of it,” he said of the technician from Thomas Jefferson Hospital. “They say it is a break from their routine.”

Dentist E. Newton Kelley agreed. He has been treating animals at the Henry-Doyley Zoo in Omaha, Neb., for almost 14 years, starting with a snow leopard that killed another snow leopard with its powerful incisors.

“At first they wanted me to remove the incisors, but a look at a leopard skull and I knew that would cause too much head trauma,” Kelley said. “So instead, we cut out the incisor nerves, then filed them down even with the other teeth.”

The dental operation was such a success it has been copied by other zoos all over the country and as far away as the Soviet Union, Kelley said. Since that first snow leopard, he has removed and cleaned teeth and has done root-canal work on big cats, bears, hyenas and apes.

“We routinely call on medical professionals and take our animals to human hospitals,” said Lee Simmons, the Omaha zoo’s chief veterinarian of 19 years. A local hospital recently performed a CAT scan on an ape to see if it had suffered brain damage from inhaling smoke.

Despite the remarkable progress, vets said they still have much to learn.

Strange diseases still strike animals even though they are vaccinated and protected from tuberculosis-carrying humans. Officials at the Baltimore Zoo were devastated several years ago when all but one of their giraffes died mysteriously.

Strange Porcupine Ailment

At the Bronx Zoo, porcupines started dying several years ago from calcium deposits in their stomachs. Zoo vets there developed an operation to save the remaining animals, but are still puzzled as to what caused the problem.

“Sometimes you have to be a detective,” said the San Diego Zoo’s Robinson in a telephone interview between treating a lemur with a high white-blood cell count and washing the wound of an accident prone tail-point monkey.

“Birds are still difficult to treat, because they mask their symptoms to keep safe from predators,” said Bush of the National Zoo, which has a bird house with several condors, an American bald eagle and flamingos. “Zoos still have a high mortality rate for birds and hippos.”

It is the animals that live long past their natural life spans that seem to bring the most pleasure to the vets, each of whom has a favorite “colleague” that has been at the zoo longer than they have.

Massa, the oldest known gorilla, had lived about 45 years at the Philadelphia Zoo when he died last year, Hinshaw said. Several times vets saved his life by removing rotted teeth that prevented him from eating.

“He was a great patient, because he always sprang right back to normal,” he said. Massa, like many elderly animals, eventually died of a stroke.

“The best thing about this work is that it is challenging and varied,” said Robinson, who watches over 3,500 animals at the San Diego Zoo. “Physically, you have to handle tall giraffes and big hippos. You have to deal with every specialty there is. You’ve got babies and very old animals--mammals, birds, rodents, reptiles.

“It’s labor-intensive,” he said, “but you have to apply technology with understanding. You have to know animal behavior, but we’re talking about quite a number of different animals.”