Ask Dr.Petra.com
Excellent information on dozens of cat health problems in clear cut, down-to-earth words. Dr. Petra Drake is a veterinarian on the San Francisco Peninsula who practices in a mobile veterinary hospital

Cold River Veterinary Center
Case histories on pets with various diseases. Information on nutrition, along with instructions on a home made diet.

Feline CRF Information Center
Also known as Avatar's site, this is the place to come if your cat is diagnosed with Chronic Renal Failure. I have dealt with this terrible disease with two of my cats, you can read my journal of Puss and Cleo's battle with CRF.

Feline Leukemia Support
Information on treating Feline Leukemia, a Feline Leukemia mailing lists, and links to Websites with more information.

Guide to Feline Diabetes
A FAQ, information on treating diabetes, reader's experiences. a message board and more.

Harmony Animal Hospital's World of Pets
Pet care library for dogs, cats, birds, and exotic pets, pet loss resources, contests, pet postcards, pet classifieds, free pet screensavers and desktop themes, create your own pet website, Pet Links Directory, and losts more from this award winning, AAHA-accredited animal hospital.

Max's House
Save The Animals Rescue Team has created Max's House, which has a wealth of information on feline health. A little difficult to navigate, but lots of great information.

Petagonia.com
An annoying amount of pop-ups, but there's good information here, including how to give your cat CPR and what to put in a first aid kit.

Radiocat  
Information on treatment options for hyperthyroidism.

Veterinary Information for Cat Owners
This is an alphabetical index of different cat conditions. Each link leads to a question from a cat owner, and the answer from the vet.