Animal Health
information on:
-common diseases from heartworms, intestinal parasites, flea and tick borne diseases
-toxic plants, foods, poisons, and what to do
-diseases in the news such as Avian Influenza, Canine Influenza, Mad-Cow Disease, and E.coli

Menu Foods Recall of March 2007 Up-to-date information on the recall of close to 100 dog and cat foods leading to kidney failure and even death!

BJ's Wholesale Club Recall of Pig Ears Dog treats of March 2007 Lesser known recall involving Salmonella contamination, but without any known illnesses associated with their use

American Veterinary Medical AssociationThis site is a good starting point to learn more about a variety of topics, including feline injection-site sarcomas and the latest subjects in veterinary medicine

Companion Animal Parasite Council
This website will answer your questions regarding Fleas, Ticks, Intestinal Parasites, Ear/Skin mites, and Heartworms...sounds a lot like an episode of "Fear Factor"!!

Heartworm Society   
Everything you ever wanted to know about heartworm disease can be found here!

National Animal Poison Control Center
This is the website of the National Animal Poison Control Center. It includes a library, links to other sites, and phone numbers for the poison control center. 
Plants Toxic to Animals, Introduction -- Vet Med Library, UIUC
A lot of information about toxic plants can be found here. You can search under common name or scientific name of the plant.
USDA Animal and Plant Health Inspection Service
The USDA maintains this website with information on a variety of animal health related topics, including the latest news on such things as Mad Cow Diseases, foot and mouth disease, and many other things. 

West Nile Virus
This site is maintained by the Centers for Disease Control in Atlanta, and has the latest information on the spread of West Nile Virus in the US, as well as information on disease transmission, symptoms, etc.