Hypericum perforatum is toxic to cats, dogs and horses. The reported severity is mild. Also known as Common St. John's-Wort.
If your animal ate this plant, call your veterinarian, the ASPCA Animal Poison Control on (888) 426-4435 or the Pet Poison Helpline on (855) 764-7661. Fees may apply.
Photosensitivity Dermatitis
The color of each symptom follows the severity scale above.
Hypericum perforatum, commonly known as St. John's wort, is a flowering plant in the family Hypericaceae. It is a hairless, perennial herb with woody roots, yellow flowers marked by black glands, and leaves that appear perforated due to translucent glands, producing thousands of seeds per plant.
Use of H. perforatum may produce adverse effects when combined with other antidepressants through an increase in brain serotonin levels called serotonin syndrome, which may be life-threatening and is associated with rapid heart rate, acute hypertension, mydriasis, and fever. Photosensitivity and acute neuropathy upon sun exposure, and reduced response to chemotherapy are other possible effects. Common side effects of St John's wort products are headache, nausea, fatigue, dry mouth, sleepiness, and gastrointestinal upset. It should not be consumed during pregnancy and breastfeeding.
Also recorded as Common St. John's Wort, Gammock, Goatweed, Herb-John, Klamath Weed and Penny-John.
Countries with the most wild observations, from GBIF data.