Treat the Immune System, Not Just the Infection

If your dog has had no adverse reactions to Revolution, then I would stay with it. People living in such states as Florida and Texas where there is no significant winter die-off of fleas and other noxious insects are in a bind. The benefits of new-generation anti-flea and anti-tick drugs might outweigh the risks to most animals, provided the animals are not over-vaccinated and are on a good, healthful diet.

Dear Dr. Fox:

In one of your columns, you answered a question about hyperthyroidism in cats.

My 18-year-old cat was found to have this condition in 2005. I tried an oral Tapazole regimen, but she became very ill. I found out later that close to 20 percent of cats tolerate Tapazole orally.

My vet suggested a transdermal application of Tapazole (methimazole) applied to the skin part of the ear. She has been able to tolerate this, and it has lowered her thyroid for close to two years. The last blood work showed the T4 was slightly elevated, so I have increased the dose from once a day to twice.

I would suggest to your readers who have older cats with hyperthyroidism that can't tolerate oral Tapazole and are not candidates for surgery or radioactive-iodine treatment to ask their vets about transdermal application of methimazole. They'll need to find a compounding pharmacy to make the cream -- it's not that expensive.

Also, because kidney failure is usually concurrent, they might get the BUN and creatinine checked. My vet has put my cat on Epakitin, which is added to her food. Her last blood work showed BUN only slightly elevated and creatinine actually down.

M.I.K.

St. Louis