Safety verdict
Consulted references classify the plant as toxic or irritating for that pet type.
Pet ingestion lookup
My dog ate St. John's Wort - what should I do?
Hypericum perforatum
Potentially toxic
Contact your veterinarian or an animal poison-control resource now, especially if any amount was chewed or swallowed.
Verified against ASPCA/provenance audit 2026-05-06 on May 6, 2026.
Signs to watch for
Photosensitivity, dermatitis, gastrointestinal upset, and lethargy.
Escalation note
The plant contains hypericin, which can cause increased sensitivity to light and skin inflammation. Seek veterinary care promptly if ingestion is observed or suspected.
What to watch for
ASPCA reports photosensitization manifesting as ulcerative and exudative dermatitis. Watch for open, oozing sores on the nose, ear edges, and lightly furred skin, especially after time in the sun.
Time window
Specific onset and recovery timing are not documented in the ASPCA listing.
When to call the vet
Call when you see weeping or ulcerated skin lesions, persistent irritation, or progression after suspected exposure to the plant.
What this means for your dog
Dogs: hypericin is the active toxin, and the headline danger is photosensitive dermatitis — ulcerative, weeping skin damage on parts of the dog that take sun (nose, ear margins, belly) after ingestion or contact with the plant.
Sources: ASPCA (no first-aid guidance).
Poison-control resources
This page summarizes source-bound plant-safety information and is not veterinary advice.