Dr. Doug Mader's - "To Your Pet's Health"
Sunday, January 24, 2010
Feline Infectious Peritonitis is Difficult to Diagnose and to Treat

By Dr. Doug Mader

Q. I took one of my cats to another veterinarian and I just need a second opinion.

I don't know what to do about my cats ... I adopted a 5-month-old kitten from a local shelter about two months ago. I did this so my other cat could have some company.

I met a lady with a 3-month-old kitten she had just adopted from the same shelter where I adopted mine. Her kitten was in bad shape ... swollen abdomen, eyes crusted shut and runny nose. She said it was positive for FIP [feline infectious peritonitis].

So I thought I would test my kitten since he came from there. Sure enough, he tested positive, too. He is not yet showing any signs of FIP, however. I just don't know what to do. Now I'm concerned about my original cat, who is four years old. I'm worried he has it. I'm going to get him tested on Monday.

What do I need to do? Please help me. Can they live with this virus? I recently vaccinated him. Could the vaccine have anything to do with his test results? Thank you.

-- A.

A. Which cat did you vaccinate? The original cat or the new kitten? The FIP vaccine will make the test turn positive. In fact, a single vaccine can make a cat false positive for up to five years.

The FIP vaccine has not been proven to be effective and is not a recommended core vaccine by the American Association of Feline Practitioners or the American Animal Hospital Association. My hospital does not use it for those reasons.

If your original cat is not showing signs of FIP, I would just watch it for now. FIP does not transfer horizontally (cat to cat) easily, so there is a good chance that both of your cats will be fine. Just watch them carefully and if you think you see any problems, you can get them further testing. Less than 10 percent of antibody-positive cats ever develop the disease. FIP is a very difficult disease to diagnose for reasons too involved to go into here. So a single positive test, although it is of course worrisome, is not definitive. There are more specific tests that can be performed if needed.

Q. Can you settle something for me? I have an ongoing argument with my husband about dog and cat food. He says it is OK to let the dog eat the cat's food, and I say it is bad for the dog. But I heard that it is OK if the cat eats the dog's food? Is that true? Thank you. I know he will listen to you.

-- Susan, Big Pine Key

A. You are correct! Cats have a higher requirement for protein in their diet. As such, commercial cat foods have a much higher level of protein in their food than commercial dog food. If a dog eats a bite or two of cat food, it is no big deal. However, if all the dog ever eats is cat food, the higher protein levels will eventually cause irreversible damage to its kidneys.

If a cat only eats dog food it will not be harmed, it will just not be as thrifty as it should be since it will not be getting enough protein in the diet. The cat will have to eat more food to get the required amount of protein and this excess intake will lead to obesity.

Dr. Mader is an ABVP board certified veterinary specialist practicing in the Keys. Send your questions to Mvh525@aol.com.