ISOLATION AND DISEASES
Keep foster cat(s) from your own cats and from non-litter mates until the health of the cat has been determined. Isolation is keeping the cats from sharing food & water bowls, litter boxes and licking each other. The best way to foster a cat is to put in a spare bedroom, bathroom, or keep in a cage big enough to house the cat or kittens, food/water and a litter box.
note: Daily exercise is important for any cat caged. Use one litter scooper per litter of kittens to avoid passing diseases through feces.
FeLV (feline leukemia): Kittens 10-12 weeks of age can be tested when the mothers immunities leave the kittens body. The incubation in cats for Felv is 2-4 weeks. Some veterinarians will test younger, but will usually recommend re-testing. Usually passed through feces, saliva, food bowls, and in utero.
FIV (feline immunodeficiency virus-or cat AIDS): Can be tested with Felv. Consider re-testing again after 4-6 months due to the time it takes for the antibodies to register in the blood test. Usually passed through bites or in utero, but can be passed by feces and food bowls.
FIP (feline infectious peritonitis): There is no accurate test for FIP until the final stages of the disease, leaving any cat at any age a candidate to be either a carrier of FIP or an infected cat. This disease alone should make a rescuer think twice before ever merging a foster cat in with owned cats. FIP is known to pass in utero, but studies are uncertain at this time how else the disease passes.
Distemper: The incubation for distemper is 3-14 days, so a 14-day incubation should rule out this disease.
Rabies: There is currently no rabies epidemic here in California. (Legislation to make vaccinations mandatory in California is under way.)
Ringworm, mange, roundworms, tapeworms, and ear mites: Non-deadly, contagious diseases such as these should be dealt with before merging the cats in with other cats.