Animal Parasites, Poisons, & Toxic Plants
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"!!
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
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 (via CDC)
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.