People often try to help stranded dolphins by pushing them back into the water, only to have them re-strand and eventually die. They don’t understand that the stress of stranding has created a host of new problems that threaten its survival, in or out of the water. At least Baker D would escape that fate. We would carefully stabilize him; if he made it, we would begin the long process of rehabilitation. Though I knew the odds were probably against us, I felt that Baker D was a strong candidate for eventual release. Whatever the outcome, we would learn something from the case.
We started supportive therapy right away, first by injecting Baker D with a general sedative. We placed a catheter into a vein in his tail fluke so we could give him a variety of IV drugs, including more sedative (Valium), corticosteroids, antibiotics, and propranolol, a drug that would lower the dolphin’s heart rate and protect the heart tissue. Then we hooked up a rehydration fluid drip for his transport to The Marine Mammal Center, a relatively short thirty-minute drive.
Staff had readied a soft-sided pool for Baker D, twenty-four feet in diameter and three and a half feet deep. With our lab technicians prepared to analyze the samples, we took blood for diagnostic and research purposes, including DNA testing, weighed him, and carefully moved him to the pool in a stretcher.
The moment we lowered the dolphin into the water, the real work began. Though the Center employs fifty people full-time, including three veterinarians, a group of about six hundred volunteers performs the bulk of the day-to-day hands-on animal care. These incredibly dedicated, caring people are essential to the critical care of stranded animals. Over the following weeks, they would nurse Baker D.
Initially, Baker D could neither swim nor support himself in the water. So our volunteers fashioned a special sling made of floats and neoprene to help keep him afloat. Two people at a time stood in the water with the dolphin to guide him gently around the pool, preventing him from listing or sinking and injuring himself. On that first day, I also stayed with him for several hours, monitoring him and helping to develop a treatment plan with the rest of our excellent veterinary team. The next day, Baker D already appeared stronger. Within a week, he’d progressed significantly: his appetite had picked up and he’d adjusted to the people caring for him. He was still very weak, however. We had a long way to go.
For the next several weeks, our volunteers nursed the dolphin around the clock, often standing for hours in the cold water and misty coastal air. They fed him regularly, dosed him with medication, and kept detailed records for every minute of the day for several weeks. No one voiced a complaint, only concern for the special patient under their care. I can’t say enough about the outstanding group of volunteers that is the heart and soul of The Marine Mammal Center. These are people who always try to do the right thing, who strive to improve themselves and the world around them, who simply care.
Gradually, Baker D became able to navigate the small pool on his own. As he continued to gain strength, we knew he’d need a deeper pool where he could get more exercise and conditioning for a potential release. We called the Long Marine Laboratory at the University of California, Santa Cruz, whose staff graciously agreed to take Baker D and give him the space he needed. Another dedicated team of people took over his care. Though we’d all bonded to Baker D, this was a happy day. We were excited and proud to see a live animal leave the Center—on its way home.
Before long, Baker D was swimming in the big pool with speed and strength. It was time to plan for his release back to the wild. The first step was to review the conditions in which we’d found him initially.
Strandings often occur in areas where the coast slopes very gradually into shallow water, a geographic feature that makes echolocation, the system dolphins use to navigate, more difficult. Changes in sea level associated with global warming may play a role in the shallow-slope effect. Some believe noises associated with human activity, like boat engines, drilling, mining, and military operations, have a lot to do with strandings. Underwater noise may interfere with the dolphins’ ability to navigate, damage their hearing, and even cause them to surface too quickly, resulting in “the bends.” A group of dolphins can also strand when the dominant animal in a group becomes disoriented and leads the rest of the pod to disaster.
Another possibility in Baker D’s case—and our greatest concern from a medical point of view—was the presence of an infectious disease we hadn’t been able to diagnose. If a bacterial or viral infection had sickened him and caused him to strand, the same disease could be a danger to other dolphins when he was released. Perhaps toxins, whether from human or natural sources, had affected him.
However, we’d found no evidence of any infection. No other dolphins had stranded at the same time; nor were there reports of any toxic spills during the period in question. Though there could have been other contributing factors, we believed that Baker D had simply made a mistake. A young, curious, and inexperienced male, maybe he’d ventured away from his pod hunting fish, unaware that he’d strayed too far. Maybe he’d gotten too close to shore and had been pummeled by waves onto the rocky beach. Or maybe he’d encountered an aggressive group of other dolphins or a potential predator that had chased him into the rough, shallow water.
Now we had what appeared to be a healthy dolphin living safely in a pool. How could we ensure we’d done our best to prepare him for a return to the ocean? Would he be able to find his pod?
We reviewed the established guidelines for releasing stranded dolphins. The animal should be in the best possible physical shape, free of diseases that might pose a danger to healthy wild animals; it should be fitted with a tracking device and released in the vicinity of members of the same species. We knew of a group of bottlenose dolphins that frequent Monterey Bay, coming close to shore at a certain stretch of beach almost every day. Our best guess was that Baker D belonged to this group of dolphins. So when, after two months of intense rehabilitation, we decided he was ready to go back to the wild, we made plans to release him in the bay.
On the day of his release, we fitted Baker D with both a VHF radio tag and a satellite-linked tag on his dorsal fin. These instruments are designed to detach themselves after approximately 250 to 300 days, their expected battery life. As soon as we spotted the group of wild dolphins, we headed out to sea by boat with Baker D safely aboard in a specially designed stretcher. About two hours later, we gently lowered the dolphin to the surface of the sea, positioning him to face the group of dolphins a hundred yards away. Once free of the stretcher, Baker D dove down, turned away from the other dolphins, swam under our boat, and disappeared under the water.
Our radio-tracking receiver picked up the sound from his VHF tag just once, as he porpoised out of the water—somewhere out of our sight. He swam away so fast that we never heard him again. Though his behavior was not what we’d expected, we were generally pleased with the outcome, proud to have completed such a rare but satisfying task. A job well done, or so we thought.
For the next few weeks, we received daily transmissions from Baker D’s satellite-linked tag. Information about his location was transmitted to a satellite and then downloaded from the Internet to generate a map showing his precise postrelease travels. Initially, Baker D seemed to be heading north toward San Francisco. But then he turned around and moved very quickly southward, reaching the Channel Islands off Santa Barbara. He made this trip in a little over a week, a distance of approximately 280 miles.
We couldn’t help wondering why Baker D had moved so rapidly away from the area that had seemed natural for him, populated by other bottlenose dolphins. Could he be disoriented? Had we missed a disease, one of those that can cause permanent brain damage?
Once near the Channel Islands, Baker D’s signals showed that he moved only small distances and stayed very close to land. Three weeks after his release, he was barely moving from one day to the next. On day seventy-six after release, the satellite-linked transmitter sent its last transmission. Not a good sign. We began to assume the worst.
At the Center we reviewed the pattern of satellite-location signals. The data seemed to indicate that Baker D had died. The relative lack of movement could mean that he’d been floating lifeless in the water. Thereafter, his body would have sunk to the ocean floor.
We were devastated. The volunteers and staff of The Marine Mammal Center and Long Marine Laboratory, the lifeguards and boat operators—we’d all worked so hard to give Baker D the best care, make the best medical decisions, and create the best possible scenario for his successful release. We wondered what we could have done differently. Maybe we should have tried to find a home for him in an aquarium. Perhaps we should have released him sooner or rehabilitated him longer. Were there other diagnostics we could have performed to find out what was wrong with him?
Two weeks after the last satellite signal, the Center’s marine biologist, Denise Greig, and a number of people from Long Marine Laboratory, including the lead husbandry manager, Brett Long, decided it was worth chartering a research flight to have a look for Baker D’s body. They hoped to gain some—any—information about what had happened to him. Even if the satellite-linked transmitter had failed, perhaps the VHF radio transmitter was still functional and would lead them to his body if it had washed up onshore.
I wasn’t on the plane, but Denise and Brett told me all about it:
It was a stormy February day when the plane set forth on its grim mission. The clouds were heavy with rain, the rough weather buffeting the plane. As the day wore on, the plane flew intersecting search patterns. The crew was quiet, concentrating and listening, intent on picking up even the faintest signal from the radio transmitters in their head-phones. Dusk was coming on and the fuel gauges showed the flight could not continue much longer.
Suddenly, the dark clouds parted and beams of golden sunshine shone down on the deep blue sea. Bright rays reflected off the peaks of the waves. A rainbow appeared in the late afternoon sky. The crew heard a faint “beep-beep-beep.” It stopped and started again. Then it got louder and clearer before disappearing again. Illuminated by glowing sunlight, a large group of bottlenose dolphins—250 or more—suddenly sprang into view, moving fast. Right in the center, broadcasting his signal loud and clear every time he cleared the surface of the water, swam Baker D.
___
Months later, once the genetic analysis was completed (these special tests require a lot of time), we learned that Baker D didn’t belong to the group of dolphins near Monterey Bay. He belonged to another well-known group of animals, the group that lives near the Channel Islands. Baker D was never lost. He knew all along where he was and where he belonged.
ABOUT THE AUTHOR
Martin Haulena graduated from the Ontario Veterinary College at the University of Guelph in 1993. He completed a clinical internship in aquatic animal medicine at Mystic Aquarium in 1996 and a master’s degree in pathobiology from the University of Guelph in 1999. He served as the staff veterinarian at The Marine Mammal Center in Sausalito, California, for nine years, and is currently staff veterinarian at the Vancouver Aquarium in British Columbia. Dr. Haulena’s special interests are in the medical management of aquatic animals, particularly marine mammals, with emphasis on innovative diagnostic methods such as MRIs, endoscopy, and ultrasonography, developing safe anesthetic protocols, and improving surgical techniques. Veterinary students from around the world study aquatic animal medicine each year under the direction of Dr. Haulena. His professional affiliations include the International Association for Aquatic Animal Medicine, the Wildlife Disease Association, and the American Association of Zoo Veterinarians.
V
CROSSOVER
Myriad anatomical and physiological differences exist among the animal groups, creating a special set of hurdles for the zoo vet. Even closely related species with the same condition may show different signs. The best medicine for a mammal may not work for a bird, reptile, amphibian, fish, or insect.
Fortunately, the basic principles of medicine do apply across species—human, domestic, and wild. Many vets who work with wild animals have also practiced on domestic animals at one time in their careers. Veterinary medicine for dogs, cats, horses, cows, and, to some extent, poultry is the basis of our formal education. From these species, we learn to extrapolate. Reptiles, for example, are evolutionarily closest to birds, so there is some crossover to chicken and turkey medicine. The more open-minded and flexible we are, the better we perform as zoo vets.
Kidney failure, for example, leads to a buildup of toxins in the blood that needs to be flushed out. The treatment is a combination of fluid therapy and modifications to the diet, plus antibiotics or other specific medicines, depending on the cause of the problem. In severe cases, dialysis can be used to keep the patient alive. When faced with a case of kidney failure, the zoo vet will typically review how this problem is diagnosed and treated in other, related species. The next step is to modify and fine-tune it to the animal’s needs, with attention to the specifics of its species—physiology, anatomy, and disease susceptibility.
For example, an elephant with kidney failure becomes ill very rapidly. Such a patient requires vast quantities of fluids, over one hundred gallons a day, delivered intravenously and continuously if possible. How are these given? The ear veins work well if the elephant is trained to stand still for an intravenous catheter. Or the fluids can be given rectally with a garden hose, a technique also used for horses. Since acute bacterial infection is often the cause, strong antibiotics must be delivered quickly. Such a treatment plan requires a team of people and swift action.
By comparison, a desert iguana with kidney failure develops clinical signs much more gradually. It may show no signs of overt illness until just before death. Often its problem is not infection but rather a gradual buildup of precipitated protein by-products in the kidney. Because this species is evolved to conserve water, its cardiovascular system can handle only tiny amounts of intravenous fluids. An iguana in need of fluid therapy gets it just ounces at a time, once a day, under the skin. The subcutaneous delivery ensures slow, safe absorption.
Even related animals differ in their expression of the same disease. Most cats, domestic or exotic, develop kidney failure as they age. Some can live for years with this illness without showing signs, particularly the big cats from African and Asia. When a lion or tiger does become ill, it often responds well to a single treatment with fluids (under anesthesia, of course) and will feel better for months afterward. In contrast, cheetahs develop kidney failure at an earlier age and succumb to it more quickly, usually within a year.
In this final group of stories, zoo vets look to the experts in domestic animal and human medicine to diagnose and treat problems in various animals. Several seek help from talented medical professionals who willingly donate their expertise and time. The patients that benefit include a goldfish, a red kangaroo, a polar bear, a pair of weedy sea dragons, a giraffe calf, and a Nile hippo.
Lucy H. Spelman, DVM
Tulip
by Greg Lewbart, MS, VMD
The corners of the stiff cardboard box were mashed and crinkled like so many miniature accordion bellows. When the UPS man slid the container across the cluttered counter, you could hear water sloshing back and forth, and the box rocked gently as its small internal waves pushed to break free.
“Initial on the X,” the man said, handing me a clipboard. “Live fish, huh?”
“Well, I hope so,” I said, scribbling my initials somewhere close to one of the many X’s littering the sheet of paper. I handed the clipboard back. Instead of turning to leave, the UPS man looked anxiously at the box and then at me.
“When you gonna open it?”
“Right away,” I said, surprised at his interest. “I’m going to open it right now.”
I reached into my lab coat pocket for a pair of suture-removal scissors. They come in handy for all sorts of things, in addition to removing stitches. Holding them open and using one sharp edge, I sliced the wide piece of transparent t
ape along one edge of the box. I flipped back the large brown tabs to reveal several sheets of classified ads from the August 1993 Des Moines Register. At this point, the UPS man leaned over the box as if peering into a volcano. Tossing the newspaper aside, I snatched the double plastic bag from its cardboard hole. When I held the bag above my head so that the fluorescent ceiling light shone through it, we could both see an apple-sized orange-and-white blob swirling in the cool milky water. All that was left in the box was a perspiring, thawed ice pack.
“It’s alive. Sure looks alive, anyway,” the UPS man remarked.
“Yes. Yes, it is,” I said with a smile. Then I addressed the fish, eye to unblinking eye. “Nice to meet you, Tulip.”
“Tulip? You mean this fish has a name? Like it’s some kinda pet?”
“Of course,” I said to the startled deliveryman. I walked Tulip over to a running aquarium and floated her, bag and all, on the water’s surface. This would help her acclimate to her new environment. Once she was safely afloat, I grabbed a blue plastic folder that had been lying next to the aquarium. “See. Here’s her medical record.”
“What’s she got? What’s she here for?”
“Probably has cancer,” I said as I fiddled with the filter and checked the aquarium’s water temperature. “Won’t know for sure until we’ve run some tests.”
The Rhino with Glue-On Shoes Page 19