Not Quite a Cat-astrophe

This summer, while my healthy young successor in writing this column was striding across Alaska in the company of his healthy young dog, I was behaving like a middle-aged couch potato, staying home and learning how and why to shoot my middle-aged cat. That's not as bloodthirsty as it sounds. The family cat got sick, then got a surprising diagnosis: diabetes mellitus. He needs insulin shots to stay alive.

Dr. Becky Lee, a Fairbanks veterinarian who owns a diabetic cat, gave me a reassuring overview. There's no unusual plague of diabetes among pets in the north, but it's not rare. She hasn't seen it among pet rodents, has heard of it, but not seen it, occurring in ferrets, and has encountered a few dogs and several cats every year with the disease. Cats often respond well to treatment.

I didn't know cats got diabetes. In fact, I didn't know much at all about the disease. I understood that the cause of "type 1" diabetes, such as the cat's illness, was a failure of the pancreas gland to produce enough insulin. I knew, vaguely, that diabetes seemed to be an autoimmune disease--one of those nasty problems caused by the body's mysterious propensity to attack itself. And, in people at least, it apparently had a hereditary component.

Well, with a research university nearby and a whole Internet a keystroke away, true ignorance couldn't hold up for long. Thus, some informal research occupied my summer. Insulin, I learned, is necessary for the transport of glucose into cells; it unlocks a cell's ability to accept this energy-providing sugar. Without insulin, the cells starve, even though the bloodstream carries plenty of sugar right on past them. Too much sugar, in fact. The excessive thirst and urination that are the typical symptoms of diabetes in humans and their pets show how the body attempts to flush out the used and unusable glucose.

But John Blake, Associate Professor of Biology and University of Alaska Fairbanks Attending Veterinarian, warned me not to assume that diabetes mellitus is the diagnosis whenever a cat floods its litterbox. Some kinds of kidney problems can generate the same symptom of too much water in and out. He didn't know of any type 1 diabetes occurring in Alaska's wild carnivores, but suggested I talk to a graduate student who is working on insulin utilization in reindeer--"They use free fatty acids more than blood sugar for energy, you know," he said.

I didn't know. That's one trouble with doing a little free-floating research; you encounter so much else that's interesting. I was thinking about a future column on reindeer fatty acids when Blake commented that viruses may play a part in diabetes, or so recent research has hinted. Doggone--more interesting information.

Eventually I did track down a short paper in the British journal "New Scientist" that discussed some of the work Blake had mentioned. According to a Swiss researcher, Bernard Conrad, and his international team, traces of a retrovirus appear in the blood of diabetes patients but not in the plasma of people serving as healthy controls for the experiment. This retrovirus, to which they gave the nonmemorable name of IDDMK22, produces a type of chemical known as a superantigen. And superantigens have been linked to the exact deadly autoimmune response seen in the pancreas glands of people with type 1 diabetes.

So maybe this one retrovirus acts in hereditarily diabetes-susceptible people to cause the disease; maybe the same retrovirus, or a similar one, causes the disease in cats. But even if Conrad's work proves correct, it's still a long way from finding a real cure for diabetes. Meanwhile, the family cat has to take his shots, whether he likes it or not.

Trust me; he doesn't like it. Gee, Ned, I'm glad you and Jane had such an interesting summer. Here, kitty, kitty...