The Hippo with Toothache (28 page)

I looked over at Tulip. She was breathing comfortably with regularly expanding O-shaped lips. Then she moved her shiny white-and-orange globoid body to the rear of the tank and squirted out several hundred tiny fish eggs, a ritual she would practice on a daily basis while she was in my care. All mature female fish produce eggs. Some, like Tulip, will lay them even without the presence of a male (fertilization is external).

Tulip was as beautiful as the flower she was named for. At least until an ugly tumor started growing on her side. She was a five-year-old oranda goldfish—
Carassius auratus
to ichthyologists. Her ancestors all lived in Asia somewhere, and she was probably at least a twentieth-generation American. Her life began as a fertilized egg with about 150,000 siblings at a fish farm. Within a few months, she was moved to a tiny corner pet store in Iowa. Young fish, or fry, go through a lot during their first few months of life. Imagine a blur of nets, plastic bags, cardboard boxes, and loud motorized vehicles.

Tulip probably lived in a tank at the Iowa store with other fancy goldfish, the kind with strange-looking telescope eyes or big yellow sacs on the sides of their faces. No doubt, the store provided these fish with the basic amenities: plastic plants, colorful gravel, and one of those scuba divers that bobs up and down every few minutes. That guy would annoy me if I were a fish. If goldfish had teeth, they might try to bite through his air hose. Their teeth are in their throats, however. That's how they grind up hard pellets.

Fish do really like the gravel, though. It's like candy to
them. They suck up pieces of it, swirl it around in their mouths, and spit it out, swallowing the algae and bacterial slime that covers each little stone.

Tulip lived in the store for only about five weeks. Her owner spared no expense on a new aquarium, double the size of the group tank at the store. Gone were the plastic plants, diver, and dozens of other fish competing for food—and attention. Instead, Tulip swam among real plants. She had an automatic feeder that fed her the same time every day. Her weekly treats included a fresh pea or a freeze-dried worm.

According to her owner, Tulip had looked the picture of health until six months before, when the lump appeared on her side. It grew quickly, although if you looked at the fish from the healthy side, she appeared normal. From this description, I couldn't recommend the best course of treatment, so her owner agreed to send her all the way to North Carolina for a thorough exam.

Radiology was a breeze for Tulip and the hospital staff. She was the star patient of the day. No barking. No scratching. And no shedding! She lay on the plastic-covered X-ray plate like a big slimy dinner roll. Her breathing became more rapid out of water, but she didn't struggle at all. Once the technician had pushed the button to make the exposure, I was there to scoop her up and plop her back into her transport tank.

We took two views, one from the side and another from the top. The radiologist on duty marveled at their clarity and beauty. Fish radiographs always look beautiful to me. The delicate bones form a lacelike pattern. Aquatic animals have less bone density than a terrestrial animal of the same size. Tulip's two little otoliths (ear stones), used for balance in the
water column, looked like small pearls in her head. Her pharyngeal teeth (the ones in the back of her throat) created rows of tiny white triangles.

Overall, Tulip's skeleton looked good, as did her egg-distended belly. And then there was the tumor. It had not spread into her spine or kidneys—very good news. This would also make surgery easier. Next stop, the operating room.

We anesthetized Tulip by placing her in a water bath containing a special fish anesthetic called MS-222. After about three minutes, she was asleep. The trick with this anesthesia is to keep the fish's gills submerged, adjusting the concentration of chemical in the water so the fish stays asleep. It sounds easy, but fish eyes are always wide open (no eyelids). You get used to it—your patient staring at you.

For Tulip's surgery, I was the anesthetist and my colleague, Dr. Craig Harms, performed the surgery. Craig is a reserved, humble, and extremely competent veterinarian with a soft, deep voice. Like a fuel-efficient automobile, he produces a lot from every word and action. He quietly accepted the challenge.

Our plan was to “debulk,” or remove, as much of the tumor as we could. Craig used a technique called electrocautery, using a forcepslike device that cuts and controls bleeding at the same time. He quickly removed the tumor with very little bleeding. The entire procedure took less than fifteen minutes. To wake Tulip up, we flushed her gills with fresh water. In minutes, she was back in her tank, leaving us little egg presents.

We sent the tumor to the pathology laboratory and waited about forty-eight hours for the diagnosis. The results were
grim: undifferentiated sarcoma. The fish had a malignancy that probably had not spread but was nonetheless an aggressive tumor. Even worse, we hadn't gotten it all. Repeating the surgery would do little at this stage. I informed Tulip's owner of the findings, and she agreed with me that our best recourse was to keep the fish in the hospital and consult with the university oncologist. If the UPS man wanted to stop by to see Tulip, he'd have plenty of time. (He never did. Maybe he didn't want to know the outcome.)

That's when Dr. David Ruslander entered the story. Dave is one of the most compassionate veterinarians I know. He's also one of the most opinionated. But the patient always came first. The arguments could wait for the bar or coffeehouse. Dave was thrilled to be involved with Tulip's case, and after carefully reviewing her medical record, radiographs, and biopsy report, he had a one-word suggestion: chemotherapy.

“I'm thinking cisplatin,” Dave said with authority. “It's the best one for these nasty sarcomas. And I couldn't use radiation without frying the whole fish.”

“But have you tried cisplatin on a fish?” I asked, virtually sure the answer was no. I also knew that this was a pretty heavy-duty drug with the potential for significant side effects in mammals.

“Nope,” he said quickly. “And I don't imagine anyone else has, either. But if you don't go with the chemo, that thing's going to grow back. You don't have clean margins. And to get 'em you'd have to cut deep into the musculature.”

“Yeah, I know,” I said in a somber tone. “Well, I've got to talk with Tulip's owner. See what she says.”

“No problem,” he said, smiling. “We've got some time. But I wouldn't wait more than a couple of weeks.”

Tulip stayed in the clinic aquarium for the next several weeks. She seemed fine, but close inspection of the surgery site revealed a small blip of tissue that was surely a new tumor. I showed this to Dave and he said simply, “It's cisplatin or more surgery. Or both.”

“Both?”

“Well, with this aggressive a tumor, the chemo might not be enough,” Dave said.

Unfortunately, Dave's prediction was accurate. Tulip was tranquilized for an injection of the cisplatin. We used an anesthetic just to take the edge off, which she tolerated well. But the tumor continued to grow during the next several weeks. Craig performed a second, more aggressive surgery, which cut into the underlying muscle. Tulip tolerated the second surgery well, which was followed a week later by a second and final round of injectable chemotherapy. But still the tumor persisted.

“I think my baby's had enough, don't you?” Tulip's mom said to me through hundreds of miles of phone line. “I mean, will more surgery or chemo stop this thing?”

“I don't know. We're sort of in uncharted territory,” I said.

“Maybe we should just let it run its course,” she said. “She looks a lot better than she did, right?”

“Right,” I said, perking up a bit. “She certainly looks better. And she's still eating well and laying eggs.”

“Well, maybe it's time to send her home. Can you do that?”

“Yes, of course. We'll pack her up and send her home this week.”

I don't think I ever had a more nervous night. Visions of Tulip's box falling off a truck or being misplaced in some
dark warehouse cluttered my mind from the time I closed the lid to the time I got the phone call the next afternoon. Tulip had made it home safely! Once again, she caught the attention of the UPS man—the one in Iowa. Tulip's owner sent me a photo of the deliveryman holding the box with the fish, flowers, balloons, and a “Welcome Home, Tulip!” sign.

Maybe we could have tried something more or something different to help this beautiful fish. Her case motivated us to find a new approach: we now use laser surgery to remove these tumors. But at the time, we felt as if we'd exhausted all possibilities. The tumor would undoubtedly shorten Tulip's life, but the fish would be back with her loving owner. I imagined the goldfish relaxed and happy, swimming again in her roomy tank and eating bits of fresh peas.

Gregory A. Lewbart graduated from Gettysburg College in 1981 with a bachelor's degree in biology; he received his master's degree in biology from Northeastern University in 1985. In 1988 he graduated from the University of Pennsylvania School of Veterinary Medicine. Dr. Lewbart worked for a large wholesaler of ornamental fishes before joining the faculty at the North Carolina State University College of Veterinary Medicine in 1993, where he is a professor of aquatic animal medicine. Board certified by the American College of Zoological Medicine, he is the author of over ninety popular and scientific articles about invertebrates, fish, amphibians, and reptiles, as well as the first textbook on invertebrate medicine. Dr. Lewbart has also
written two novels,
Ivory Hunters
(1996) and
Pavilion Key
(2000), both scientific mysteries that address issues of wildlife conservation and man's exploitation of the environment. He and his wife, Dr. Diane Deresienski, also a veterinarian, live in Raleigh with their assorted pets.

WHEN WE FIRST
examined Sally the kangaroo, she lay in shock on the ground. Her pupils were dilated and she showed no response to people approaching or touching her. She seemed unable to use her rear legs and lacked muscle tone around her cloaca (the combined rectal-and-bladder opening found in all marsupials). She could move her front legs in what appeared to be a coordinated manner, however.

The two rambunctious emus that had chased the mob of kangaroos, sending Sally crashing into the fence, stood quietly at the far end of the exhibit. These birds often chased the kangaroos—and each other. During particularly active chases, the kangaroos could really get going. This wasn't the first time the emus had done damage.

In their native Australia, red kangaroos live in wide open
grasslands where their strong, heavy lower bodies are an advantage. Deerlike eyes and ears give this odd and interesting species a delicate look. In fact, they are very hardy in most circumstances. Their powerful rear legs and tails give them the option of fight or flight. They can stand up to box, kick out at predators, or hop at breakneck speed. If excited, they will explode into action.

In the wild, however, they don't often encounter the tough and impenetrable obstacle of a chain-link fence. Excited zoo kangaroos may simply circle in their pen, or they may make a break for it through the fence. It's an unfortunate but common choice, given that the animal is hell-bent on fleeing. Usually the outcome is nothing worse than a very surprised and dazed kangaroo. If they hit the fence face-on, though, the impact on their upper body is huge. Sometimes they suffer severe neck injuries.

Over the years, we'd had two such cases at the Audubon Zoo in New Orleans, where I worked as staff veterinarian. We found the animals down and unable to move. Spinal injuries are not situations that can be treated easily even in domestic animals, let alone kangaroos. Our success rate so far was zero.

We moved Sally carefully to the zoo's hospital. A systematic neurological exam showed us that the injury was most likely in the spinal cord, our worst fear.

We took radiographs of her neck and chest and found that her second and third vertebrae were out of place. Because the spinal cord is not visible on a plain X-ray, we did a myelogram next. This test involves injecting a special dye into the space around the spinal cord and taking a series of
radiographs so that we can see the precise site of damage. Normally the dye moves quickly down the length of the cord and fills the space evenly. In this case, the dye marking the outline of the spinal cord narrowed just at the point where the bones looked out of alignment.

In a way, this result was a good sign. The damage had occurred at a single point along the spinal cord, involving just two adjacent neck vertebrae and not the fragile first one. All marsupials have a uniquely shaped first cervical vertebra—the first bone in the neck under the skull. These bones have deep central indentations in kangaroos, making them wing-shaped and therefore somewhat unstable. At least Sally's first vertebra had not been damaged.