U.S. Food and Drug Administration
Equine Research Centre
Equiworld.net
Ministry of Agriculture and Food Ontario B.C.
Floridahorse.com
HorseMatters.com   First AID Info
Purdue
Cornell
Newrider.com
University of Florida
Horseweb-uk.com
Ohio State University
West Virgina University
Canadian Poisonous Plant Information
USDA/ARS Poisonous Plants Research Laboratory, Logan, Utah
Poison Information on the Web (University of Arizona)
Poisonous Plant Databases
Dermatology Database
Canadian Poisonous Plants Information System
Guide to Poisonous Plants - Colorado State University
Indiana plants poisonous to livestock and pets
Poisonous Plants of North Carolina
Nova Scotia - Poisonous plants and Poisonous fungi [illustrated]
Plants toxic to animals [University of Illinois]
PLANTOX -American bibliographic Poisonous plants database.
Poisonous Plants of Veterinary Importance - University of Pennsylvania
Poisonous Plants of the southeastern United States