The ASPCA offers a database of toxic and non-toxic plants, with photos, to dogs, cats, and horses. You can see a list that affects only one of those three species, or view all of them.
This list contains plants that have been reported as having systemic effects on animals and/or intense effects on the gastrointestinal tract. Please note that the information contained in the ASPCA plant lists is not meant to be all-inclusive, but rather a compilation of the most frequently encountered plants. If you think that your animal is ill or may have ingested a poisonous substance, contact your local veterinarian or, for a fee, the ASPCA's 24-hour emergency poison hotline.
ASPCA Animal Poison Control Center
1-888-426-4435
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