Expert: Jessica - 11/2/2009

Question
A stray cat showed up at my mom's house 3 wks ago. My mom kept her while trying to find the owner. She seemed healthy. She drank a lot of water there but was a picky eater and had bad smelling stools. No one claimed her so I brought her home last night to live with me and my cat, Frank. She drank a lot and ate quite a bit of Frank's food. A few hours later one of her eyes started running and she began sneezing a lot of snot out on everything. Today she is still sneezing and runny eyed, still drinking and eating, but has horrible smelling diarrhea.  Does this sound like a common cold to you? The diarrhea possibly from the new food she ate?  My vet isn't in her office today and I am wondering if I should try to find another vet to see today, or if it's ok to wait 2 days for my vet to return?  I am worrying about Frank getting sick from her.

Answer
Hi Lainie.  It's always a good idea to keep a new cat isolated until they are checked out by the vet, because they certainly can carry contagious diseases.  Try to keep her separated from Frank, and wash your hands with soap between handling the two.  As long as she's eating well, a day or two of the sniffles and diarrhea is not necessarily going to kill an otherwise healthy adult cat.  But if she's a kitten or is already underweight, you should probably seek the attention of another vet sooner.

Some of the things we worry about with upper respiratory and eye infections are feline herpes and calici virus, which Frank should be vaccinated against if he has received yearly vaccinations.  But also, there is chlamydia, which is bacterial.  Most cats don't receive protection against this as part of their regular vaccinations.  The good news is that this, along with other bacterial infections that can cause these symptoms, is curable with antibiotics.  The bad news is that it's contagious through nasal and eye secretions, so if you don't wash your hands between petting the two, or if they share any belongings, it can spread.

The diarrhea could have been caused by the change in diet and even by overeating.  However, outdoor cats nearly always have intestinal roundworms, and these are contagious through sharing litter boxes.  Tapeworms, which are not contagious but are spread through fleas, can also sometimes cause diarrhea.  Your vet can give the cat a dewormer such as Profender or Drontal that will kill all these worms, or separate dewormers for each type.  Some germs that can cause foul-smelling loose stools include protozoan parasites such as coccidia and giardia, or bacterial overgrowth in the intestines.  Prescription antibiotics are usually recommended for cats with bad diarrhea to address these problems.  One other possibility is feline distemper.  This viral infection has a high mortality rate, taking the lives of about 90% of its victims (although adults have a far better chance of surviving than kittens do).  However, this is unlikely, because cats with distemper usually won’t eat or drink, and they often vomit profusely.  If she goes off her food, though, you should get her to the vet right away, since early treatment is imperative to survival.  Frank should be protected against this disease if he had vaccinations at any time within the last few years.

While at the vet, you should have the kitty tested for the feline leukemia and feline AIDS viruses.  Both of these, especially feline AIDS, can cause compromised immune systems, so cats infected with these viruses are more likely to suffer chronic diarrhea, upper respiratory and oral infections.  Most vets can run a combination test in house and give you results in 10 minutes.  The diseases are contagious, leukemia much more so, and they are incurable.  You would need to keep her separated from Frank if she has leukemia for certain.  AIDS is only spread through bite wounds, so in friendly households, it is highly unlikely to spread.  I have kept AIDS+ cats with negative ones for 10 years now and have never had it pass between cats, but there could be a risk.

In the meantime, you can mix some pea baby food into some canned cat food to try to help firm up her stools.  One or two teaspoons mixed into a normally sized meal is fine.  Yogurt also contains beneficial bacteria that can help knock down the “bad” bacteria if that’s what’s causing her belly problems.  A teaspoon twice a day should help.

Best wishes, I hope all turns out well!

Jessica