The Hippo with Toothache

by Lucy H Spelman

  Getting the milk into Kayavak posed even greater concerns. Even if we could teach this baby how to nurse from a bottle, we couldn’t do it soon enough to get the calories she needed today, or even within several days. So we would have to start by placing the tube down her throat into her stomach and pouring the milk through a funnel, the same method we’d used for the electrolyte fluids. Annelisa and I didn’t need to be involved—the technicians and trainers could do this step. But how often?

  The calf had been nursing from her mother every twenty minutes to one hour, and we couldn’t come close to matching that frequency with stomach tubing. Realistically, we could tube-feed her three times a day. We also didn’t know exactly how much she drank each time she nursed, though we guessed it must have been several ounces. This meant large volumes of milk—up to a gallon—would have to be delivered at each of the three feedings.

  We knew we could succeed with this method at the beginning. Kayavak had tolerated the earlier fluids just fine. But would the calf continue to cooperate, or would she begin to resist us? Would the stress of being handled create new problems? Pneumonia loomed as a possible complication of stomach tubing because we’d be putting such a large volume into her stomach each time. Whales breathe through a physically separate and protected blowhole. Even so, if we overfilled her stomach or she struggled during the tube-feeding process, we could inadvertently get milk flowing back up and around the airway into the wrong place—her lungs. As in any animal, that would be a serious and potentially fatal problem.

  We would eventually teach her to drink from a bottle and stop the stomach tubing. But how many days or even weeks would that take?

  Meanwhile, our veterinary pathology team had begun the postmortem exam on Immi. Annelisa and I stopped in to check on their progress frequently. To our frustration, the exam revealed no clear answers. When an animal dies unexpectedly, as Immi did, we hope to at least learn why. There are few things more frustrating than not being able to determine the cause of death. Sometimes a preliminary examination leads to a sudden “Aha!” moment in which an obvious answer is found, but that wasn’t the case here. As the pathologists continued their work, moving from a gross examination on to the process of evaluating tissues microscopically, we had no definitive explanation for what happened. And we had very few clues.

  We agreed that the most likely explanation for a fatal illness that occurred so quickly was an overwhelming bacterial infection. If we were right about this diagnosis in the mother, what did we need to consider about the calf? We hedged our bets and added antibiotics to the emerging treatment regimen for Kayavak. As to the source of the infection, we began a series of tests to look for unusual bacteria in the food or water. It would take at least twenty-four hours before we’d have any results. Eventually, we confirmed that Immi died from erysipelas, an overwhelming bacterial infection known to cause rapid death in marine mammals.

  Immi’s loss hit us all hard. She had been one of the aquarium’s first beluga whales; Kayavak was her first calf. This pair of charismatic, intelligent, and highly social animals had also become Chicago’s media darlings. The staff and public adored them. Together they represented the success of our beluga breeding program. Now one was gone forever and the other was in trouble. We also worried about the rest of the aquarium’s beluga collection. We could only hope that what had killed Immi would not strike again.

  We took frequent breaks from Kayavak to look in on the rest of the whales. We also wondered what they sensed or understood about the events of the last few days. Experts who study elephants have observed a mourning process when a herd member dies. Was this occurring with our whales? Does a whale grieve as we do? We didn’t know. But we did know one thing: we wouldn’t let them out of our sight. We needed to reassure ourselves that everyone was healthy.

  Our second option for Kayavak was to foster her onto another whale, Puiji. As the night wore on, we paid particular attention to this female who had given birth a few weeks before Immi. Sadly, her calf survived for only a short time. We couldn’t be certain, but Puiji would very likely resume lactating if presented with a calf.

  This option appealed to us for several reasons. Not only would the calf be drinking the real thing, she would have the companionship during her infancy of a mother whale. It’s not surprising to see a beluga calf nursing well into its second year. Though Kayavak had hit every milestone, at five months old her natural weaning time was still many, many months away.

  But here too there were challenges to consider. Kayavak had never actually been in the same habitat with Puiji. The two might not bond. The adult whale could be aggressive or uninterested. She might not produce any milk. How much time could we give these two to forge a relationship before we’d feel compelled to intervene and feed Kayavak? And could we determine if the calf’s nutritional needs were being met, when and if nursing began? Ultimately, this option left a lot to chance. We had to decide how comfortable we were with the idea of letting go. The calf’s fate would be largely out of our control in this scenario.

  Another pool drop just after midnight to give the calf a second dose of fluids left staff tired. Kayavak, on the other hand, acted as if the night had just begun. She looked for attention and repeatedly swam over to the trainers stationed poolside. Clearly, she wanted them in the water with her.

  We took her cue and started a new rotation: swimming with Kayavak. Trainers lined up for this assignment. It hardly felt like work. They swam alongside the curious whale or floated on rafts within reach, allowing her to brush their hands as she passed nearby. If Kayavak was grieving, she was also pragmatic. She learned very quickly where she could get the attention she wanted. These wet-suited people might not be great swimmers, but they were acceptable as new companions.

  I often marvel at how much we know about these animals, yet how much more we need to learn. Although you won’t find the definitive textbook on rearing orphaned beluga calves on your library shelf, you will find, among the ranks of veterinarians the world over, a willingness to innovate, to extrapolate, and to share experiences. We tapped into the aquarium world network again to explore our third option for Kayavak: weaning her straight onto fish.

  No one had tried this approach in a whale calf. But we heard several encouraging stories about dolphins. Young dolphins will start eating whole fish even while continuing to nurse. We heard about one dolphin successfully weaned from nursing at six months of age. Although the information trickling in from our colleagues did not exactly amount to a peer-reviewed scientific paper, it did represent the most intriguing and, in many ways, the least risky of our three choices. Conventional wisdom was that a six-month-old whale needs milk. But if a six-month-old dolphin could survive on fish, why couldn’t a whale calf? Plus, we were sure we could train Kayavak to eat.

  We met to share our ideas. Veterinarians, curators, and trainers pooled their thoughts and expertise while the aquarium’s director looked on. We called more experts, combed the literature, and borrowed a page or two from domestic animal medicine. There was no clear right answer. The only wrong answer was inaction, and so we moved quickly.

  By the first light of morning, we had our decision. We would abruptly wean Kayavak onto solid food. With this approach, we’d have control over her nutrition and intake; we could weigh her routinely, monitor her for illness, and still have the option of providing fluids and milk by tube-feeding if necessary. We’d blend aggressive veterinary medicine, expert animal care, and intensive animal training. We’d teach Kayavak how to eat and then wean her from us—sooner rather than later.

  Kayavak ate her first fish on December 27. At that session, she received three herring. Though she gave us a quizzical look, she seemed no worse for the experience. By day’s end, she’d received two and a half kilograms of fish, or about 20 percent of what we’d calculated she would need each day. We continued to supplement her with fluids and treat her with antibiotics. The next day she was up to three and a half kilos. By week’s end, she was approa
ching trainers for food as well as attention. After three weeks, she was eagerly taking fish from the trainers.

  As expected, the whale lost weight at first, but she remained bright-eyed, energetic, and responsive to her human caretakers. She handled her new diet well, and her appetite was growing. After two months, the calf had surpassed her original weight. She was ready to meet the other whales.

  Before Immi’s death, Kayavak and her mother had lived together in a pool separate from the other belugas. They had access to each other only across netted gates. We wanted to minimize the chance of complications during birth and limit the risk of aggression toward the newborn. Mother belugas tend to be very protective of their babies. Additionally, female whales will sometimes try to steal another mother’s calf. Now we followed a step-by-step plan to introduce Kayavak slowly to the adults, one at a time, over a period of months. Each time we opened the gate that connected her pool to the adult pool and began an introduction to a new whale, we felt considerable trepidation.

  Immi had been the dominant animal in the pod before the birth of this calf. Whale social behavior depends largely on hierarchy; we wondered if Kayavak would benefit from her mother’s prior status. Such social dynamics are complicated, however, and what we understood about the rankings of our beluga community was likely just the tip of the iceberg. With Immi gone, things could have shifted in ways that would be hard to predict.

  Sure enough, despite the role her mother once played, Kayavak wasn’t accorded any special status. On the contrary, she entered the pod at the bottom of the pecking order, and there were times when the older whales showed aggression toward her. But, ultimately, she held her own. Gradually she learned to navigate the society of her new pod and became a solid part of the community.

  Even so, Kayavak maintained a bond with all of us. She would throw a glance toward her human companions now and then, as if to let us know she’d made it. We felt as though she were looking back at us with a wink and a nod. Our relationship with her continues to be a special one. Now a young adult, Kayavak is an integral part of the beluga group at the aquarium. A guest wouldn’t be able to pick her out from among the other animals, but every member of the aquarium staff can identify her at a glance.

  Kayavak’s case, with its sad and startling beginning but successful resolution, made a lasting impression on me. Of all the lessons we learned that winter—about nutrition and infectious disease, behavior and environmental enrichment, tough decision making, and acceptance of risk—perhaps the most powerful were the ones we learned from Kayavak. She taught us about adaptability and survival. This endearing whale sought the care and companionship she needed to survive, and we happily provided it.

  ABOUT THE AUTHOR

  Jeff Boehm is a graduate of the University of California, San Diego, where he received his bachelor’s degree, and the University of California, Davis, where he received his degree in veterinary medicine. He completed an internship in small animal medicine in Southern California and then worked as a veterinary clinician at the Los Angeles Zoo. Since 1992, Dr. Boehm has worked at the John G. Shedd Aquarium in Chicago, where he is currently the senior vice president for animal health and conservation science and the Louis Family Conservation chair. In this position, he oversees the aquarium’s veterinary division, a variety of conservation science initiatives, and a Great Lakes conservation program. Dr. Boehm has a keen interest in aquatic conservation, specifically the role that zoos and aquariums play in fieldwork and research, and ultimately in public awareness.

  II

  TECHNOLOGY HELPS

  MRI scans produce excellent images in turtles, lasers limit blood loss during surgery in fish, ultrasound studies can detect heart disease in gorillas, orthopedic surgery works well in birds, and root canals are readily performed on lions, tigers, and bears. All of these animals are monitored during anesthesia with pulse oximetry, a measure of heart rate and blood oxygen saturation. With the help of medical technology, zoo vets arrive at diagnoses earlier, predict outcomes more accurately, and treat symptoms more successfully.

  Given the range of species and potential problems in zoological medicine, there’s sometimes a first-time technological solution. It might be the application of familiar technology to an unfamiliar species, or the replacement of a traditional medical tool with a newer one.

  The process of applying such techniques in wild animals, however, is anything but routine. Even the simplest technique may require a degree of modification, depending on the species. In order to make such adjustments, we collaborate with experts in other medical fields, including domestic and large animal veterinarians, physicians, medical technicians, and veterinary and human dentists. Adding to the challenge, most of our patients must be restrained, anesthetized, or trained for months before they will tolerate even simple technology-based procedures. A sick octopus in need of a set of X-rays, for example, requires three sets of hands and a barrel of water, with a water-soluble anesthetic available as backup.

  Radiography, the production of images using X-rays, is a good example of the application of medical technology in zoological medicine. In both humans and animals, bones and other cartilaginous structures appear white, internal organs appear various shades of gray, and air-filled structures appear black. X-ray images readily show the patient’s skeleton, including its teeth, and the outline of major structures such as the heart, lungs, intestinal tract, liver, kidneys, and bladder.

  The size and density of the animal determines the type of cassette that holds the film and the power required to produce the image. Dental film, the kind we humans bite down on while sitting in a dentist’s chair, works fine for whole-body images of tiny animals like hummingbirds, small fish, and frogs. We use standard-sized X-ray cassettes for small mammals like meerkats and monkeys, or for various body parts of larger animals—the thorax of a wolf, the abdomen of a tiger, the skull of a tapir, or the hoof of a zebra. Whether the exam is performed in a fully equipped veterinary hospital or in the field, the patient is almost always anesthetized or lightly restrained.

  Interpreting the X-ray images poses another challenge. Experience and knowledge of comparative radiographic anatomy are crucial to accurate interpretation, and even then opinions may vary. The radiographic anatomy of a gorilla most resembles that of a human, but with quite a few differences, not the least of which is the size of the hands and skull relative to the body and the presence of air-filled sacs located beneath the neck and in each armpit. Birds have air sacs too, and some of their bones are full of air cavities. But there are many differences among these species as well. An X-ray of a parrot looks very different from that of a hawk.

  With the arrival of digital photography and digital radiography, many zoo vets use e-mail to send radiographs to experts at other institutions for another opinion. As a whole, our profession has been quick to take advantage of the Internet. Not only do we use this tool for communication, it’s often the first place we look for the latest medical technology.

  Zoo vets show their low- and high-tech creativity in the next group of stories: horseshoes give a rhino relief, fiber-optic instruments help pandas, massive portable life-support systems transport whale sharks halfway around the world, orthopedic surgery helps a falcon, and frogs benefit from a new anesthetic method.

  Lucy H. Spelman, DVM

  The Rhino with Glue-On Shoes

  by Lucy H. Spelman, DVM

  THERE HAD TO be a better way to deal with this rhino’s feet. Blood dripped from Mohan’s foot pads as veterinarians and technicians worked furiously to carve away diseased tissue. These were not small feet—each one measured about ten inches in diameter. A growing pile of soiled gauze and towels littered the floor. Next, bandages would go on. Then we’d roll the rhino over to work on the other side. The blood didn’t worry us. Even if Mo lost a few pints during the trim, the 5,000-pound animal wouldn’t know it.

  In an odd sort of way, we were glad to see red. The blackened, unhealthy tissue wedged between his toes and
into the cracks of his soles had outgrown its vascular supply. His back feet were the worst. We trimmed off the outside layers until we got down to healthy tissue, which bled profusely. I watched the foot-trimming team for a minute or so, long enough to gauge how much more anesthesia time they needed. Then I turned my attention back to the rhino. Though we’d done this procedure many times before, it still felt like a big deal to put him under anesthesia.

  At thirty-two, Mo was one of the oldest greater one-horned rhinos in captivity and genetically valuable. When he arrived at the National Zoo, in Washington, DC, in 1998, three years before, everyone hoped that he and Mechi, our female, would breed. He had never bred, and we knew he had a history of foot problems. Unfortunately, the pattern continued. Though the two seemed compatible, Mechi showed more interest in Mo than he did in her and his feet continued to deteriorate.

  Fortunately, Mo handled anesthesia well. He’d stand still for the darting and slump to the ground ten minutes later when the drug took effect. Sometimes he’d go down in the middle of the enclosure, which made it easy. Other times he’d jam his great nose in a corner. We’d reposition him using a few ropes and about a dozen people. I’d put a catheter in his ear, start him on an IV filled with muscle relaxant, and then put a rubber hose up one nostril to deliver oxygen. The minute we had our first set of vital signs, the rest of the team got to work and the trimming began.

  Given his age and the ever-present risk of complications, I tended to keep Mo’s anesthesia on the light side. At the slightest indication of a problem, I could quickly reverse him (wake him up). Since this strategy meant that a loud noise or bright light could cause him to stir, we covered his eyes with a cloth drape, packed his ears with gauze, and kept a syringe full of anesthetic at the ready.