The Hippo with Toothache (15 page)

“All right, let's go! Tumaa, get the jeep behind the bull. Over there!” I yell over the whining engine noise. Ever so slowly, the bull gets larger. I raise the dart gun and begin to focus through the scope. The camel appears in the scope and is instantly gone again as we hit the next bump.

“Tumaa, we must get a bit closer. . . . Looks good.” I have the bull clearly in the scope and think,
Relax, don't shoot too soon
—
just wait, wait
. For a brief moment the motion of the jeep seems suspended and I pull the trigger. With a distinct
swoosh
, the compressed carbon dioxide pushes the dart down the barrel. Time slows, and through the scope I watch the dart streaking toward the bull's rump. I'm wishing it along, not daring to hope it will actually reach the animal.

“Tsaa
, got it!” I call. The dart is firmly stuck in the rump muscles. The tension in my body eases, my hand relaxes, and I draw a deep, grateful breath. “Take it easy. Slow down and let him get some space, no need to scare him any further.”
Slowly the intense cold is returning and my nose is now perfectly numb.
Got to watch out for frostbite
, I think. But no matter, we have our first camel.

In the distance, the bull nearly vanishes from sight in the driving snow. Then he slows and assumes a drunken pacing. He's fighting the drug effects, but I know we have him this time. After a few more minutes, he sinks to the ground and lies down. We wait, letting the drugs take their full effect.

“Looks good. His breathing is regular and deep,” Petra says as she fixes the bull with her binoculars. I get out of the jeep, shoulder the medical pack, and walk across the snow-driven plain. My patient is rapidly disappearing in a snowdrift. He does not react to gentle prodding; I wave to the others to join me.

I get down on my knees and look the bull in the open eyes while I place my pulse oximeter probe on his tongue. Beep, beep, beep, the reassuring heartbeats resound above the wind. He's at 94 percent saturation, which is near normal for the oxygen levels in his blood, despite the anesthesia. I stroke the bull's tousled hairy head and say quietly, “It's going to be all right.”

Petra is kneeling next to me in the snow. Though she has her face mask on, I can see in her eyes that she is smiling. “Okay?” she asks.

“Yeah, start putting on the collar. I'll try to get a blood sample.” I search with my finger for the jugular vein. “What a hairy beast,” I mutter. “This blood sample is not going to be simple.” Finally, the needle slips into the vein; the first few drops of blood appear and then instantly freeze. “Petra, this is not going to work—the blood is freezing in the needle.”

“Hang on, I have some warm needles in my fleece.” She hands me one.

It works. The blood slowly fills the tube, and we have our first good genetic sample. The Global Positioning System (GPS) unit mounted on top of the collar will determine the bull's location three times a day and transmit the data to our field station every other day via the French Argos satellite system. With this information, we will be able to learn more about the bull's movement patterns and determine his requirements for space and food. This data is essential if we have any hope of conserving this species for future generations. Mounted on the side of the collar is an additional unit, a small explosive charge that will activate sixteen months from now to release the collar. This sounds dangerous to the animal, but the very small charge is carefully contained in a steel casing that channels the explosion to simply remove a retaining pin. Similar collars have been used in all kinds of smaller, more fragile species like elk and deer.

The bull's head seems to be floating above the snow. The rest of his scruffy, dark brown body is covered by the snowdrift.

“We're all done,” I announce. “Let's get this animal up before he's completely snowed in.” One by one, my team members approach the bull, stroking his head. Each bids the camel good-bye in his or her own way, wishing him well for his future travels in the Gobi.

I am alone with the bull, holding the syringe filled with the reversal drug. Once it's in the vein, the animal will awaken and shortly thereafter jump up—and most probably run off. The needle once again slips into the vein and I depress the
plunger. My knee is firmly on the bull's lower jaw, fixing his head to the ground. I don't want him attempting to get up before he has the strength to throw me off.

The bull and I have been together for the past hour. The chase, the dart, and the hairy head in the snow are etched in my mind. Once he leaves to roam the Gobi, I hope that he will never again meet another human.

He begins to stir, his breaths deepen, and then he makes a first feeble attempt to throw me off. “You will have to do better than that,” I say. Finally, a few minutes later, the bull wheezes noisily and throws me into the snow. He looks slightly confused, but holds his head high and glares at me. This typical camel look lets me know he is back in charge. He gets up and takes a few wide-legged, shaky steps away from me before stopping and turning back one last time.

“Go on, be well and take care,” I tell him. “We will be watching you.”

The bull turns away, disappearing again into the driving snow.

Six months later, in the comfort of my Vienna office, I log on to the Argos satellite Web page to check up on the collared bull. It's summer in the Gobi, where daytime temperatures often reach 50° centigrade (122° Fahrenheit). The camel is moving north, tracking rainfall and good pasture. Remarkably, we've yet to see any signs of illness or injury in this bull or in any of the other five collared animals, despite the harsh conditions in the desert. Though our data is preliminary, one thing is clear: this remarkable species needs a great deal of space in order to remain healthy and survive.

Christian Walzer has been a professor at the Research Institute of Wildlife Ecology, University of Veterinary Medicine, in Austria, since 2005. He earned his veterinary degree from the University of Veterinary Medicine, Vienna, in 1990. Since that time, he has worked in rural practice and served as the zoological codirector, head veterinarian, and staff researcher at Zoo Salzburg in Austria. Dr. Walzer is recognized internationally for his expertise in working with wildlife, especially wild equids and carnivores, gained from combined years of work and study in Europe, Asia, and Africa. He has participated in numerous challenging field projects, including the transporting of Przewalski's horses from Europe to Mongolia, the study of the impact of human intrusion on the khulan (wild ass) in the Gobi Desert, and the placement of satellite-monitoring collars on wild camels. He is currently conducting various research projects in Mongolia, including landscape-level research for the conservation of the Asiatic wild ass, funded by the Austrian Science Foundation.

BECOMING A CROCODILE
veterinarian was not on my priority list when I attended veterinary school in Germany. I'd always wanted to become a zoo vet, but working with reptiles, particularly snakes and crocodiles, wasn't what I'd ever envisioned. Though I'd grown up with many animals, including dogs, hamsters, birds, fish, and a tortoise, my mother might have given me away for adoption had I come home with a snake!

But everything changed when reptiles first became my patients. They are fascinating creatures, and as I began to appreciate their place in the animal kingdom, I acquired my own reptiles, especially tortoises. To this day, they are my passion.

I'm lucky that my wife shares my fascination with reptiles and has allowed me to keep quite a few of them. However,
there is one major problem associated with my reptile keeping: many species, especially the tortoise, are very long lived. Sometime in the future I will have to make the necessary arrangements to put them in my will.

The veterinary hospital where I worked during the mid-1990s provided medical care to exotic animals kept as pets, including birds, reptiles, and small mammals, as well as wildlife patients. We also provided care for several zoological parks. One of these institutions, the St. Augustine Alligator Farm Zoological Park in St. Augustine, Florida, had a two-thousand-pound male saltwater crocodile named Gomek in its collection. He was approximately 17.5 feet in length, with a V-shaped head the size of my dinner table. Dark scales covered most of his body and huge, peglike teeth lined his jaws.

Considering his enormous size (saltwater crocodiles are the world's largest reptile), Gomek was surprisingly docile. He performed daily for tourists from all over the world during his scheduled feeding sessions. It was an amazing spectacle, actually, to watch an animal of his size gently take food items from the end of a long hook held by a zookeeper—not at all what you'd expect after watching some of the nature shows about wild crocodiles.

On my regular visits to the zoo, I'd often pass by the crocodile exhibit. Gomek appeared to be in good health, so there was little work for me to do. Sometimes we'd review his husbandry—routine feeding, cleaning, and housing protocols—with the zookeepers and curator. The crocodile was fed a variety of food items; he especially liked nutria, a member of the rodent family. He lived by himself in a large
enclosure with a spacious pool where visitors could observe him through an underwater viewing area.

On one such visit, the curator asked me to take a closer look at what appeared to be a skin infection on Gomek's tail. From a safe distance, I could see patchy white areas along the edges, or margins, of several scales near the base of his tail. The lesions looked superficial, but we agreed to keep a close eye on the condition. I suspected some type of bacterial or fungal infection and hoped it would resolve on its own, but it didn't. Though the skin problem didn't seem to bother the crocodile, the number of affected scales increased over the next few months. We decided to treat him empirically (based on observation) with antibiotics rather than put him—and us—through the stress of an exam.

Selecting an effective antibiotic for a reptile is often a challenge because little information is available on which drug is most effective and how frequently it should be given. Also, different reptile species vary tremendously in weight, ranging from a few grams (e.g., a gecko) to one ton (e.g., a saltwater crocodile). Thus the amount of antibiotic and the route of delivery vary depending on the patient.

Our initial thought was to hide the antibiotic in the crocodile's food. But we knew this form of administration might not be very effective in this species. A large cold-blooded reptile has a lower body temperature and thus a lower metabolic rate than a similarly sized warm-blooded mammal. These physiologic differences mean that reptiles metabolize drugs more slowly and/or less completely. Most antibiotics given orally to crocodiles are not well absorbed and may not reach therapeutic levels. The head reptile keeper felt
comfortable giving the crocodile intramuscular injections using a syringe attached to an eight-foot pole, though. This route of antibiotic therapy is often effective in treating bacterial skin diseases in reptiles. So we planned to try it for a month.

After about four weeks of treatment, I called the zoo as usual the day before my regularly scheduled visit and spoke with the head reptile keeper. We discussed the crocodile's skin condition, which hadn't improved despite the antibiotics. The good news was that Gomek was active and certainly hadn't lost his appetite. The major shortcoming of our treatment regimen was that we'd tried treating the problem without a definite diagnosis. So I suggested to the head keeper that we anesthetize the crocodile sometime soon to collect appropriate diagnostic samples. We needed to determine whether the lesions were bacterial and/or fungal in origin. From there, we could initiate more specific therapy. Despite the potential risks of anesthesia, he agreed. We planned to have me look at the animal again and then arrange for a full workup in the near future.

Anesthesia in large reptiles poses a number of challenges, however. Crocodiles and alligators command the same respect as lions and tigers when it comes to working with them in close quarters—all are potentially dangerous carnivores. Despite the differences in metabolic rate between reptiles and mammals, some anesthetics work reasonably well in both classes of animal. Other anesthetic drugs may have very little effect, while some, if not dosed precisely, can inadvertently kill the patient.

Once anesthetized, reptiles also behave differently from mammals. Their heart and breathing rates during anesthesia
tend to be extremely low, making it hard to judge anesthetic depth. Gomek, for example, might breathe only once every few minutes during anesthesia, and his heart rate might decrease below two beats per minute. If we did decide to anesthetize him, we'd need to be extremely careful for his safety—and mine.

The next morning, I left the hospital with a group of senior veterinary students who were looking forward to a field trip that would get them out of the clinic. They also seemed enthusiastic about the prospect of a nice lunch at the beach after we finished work at the zoo. We arrived early and completed most of our scheduled rounds by late morning, including rechecks of other patients that were being treated for a variety of conditions. Then it was time to check the crocodile.