What should I do if my cat ate St. John's Wort?

Call any time you see ulceration, weeping skin lesions, or rapidly worsening irritation following suspected exposure. Open sores require veterinary attention to prevent secondary infection.

What should I do if my dog ate St. John's Wort?

Call when you see weeping or ulcerated skin lesions, persistent irritation, or progression after suspected exposure to the plant.

St. John's Wort — (c) Thomas Gyselinck, some rights reserved (CC BY), uploaded by Thomas Gyselinck — Photo by (c) Thomas Gyselinck, some rights reserved (CC BY), uploaded by Thomas GyselinckiNaturalistCC BY

Photo by (c) Thomas Gyselinck, some rights reserved (CC BY), uploaded by Thomas GyselinckiNaturalistCC BY

Pet safety reference

St. John's Wort

Q: Is St. John's Wort safe for cats?

St. John's Wort is potentially toxic to cats. Ingestion can lead to severe skin reactions when exposed to sunlight. Please contact your veterinarian immediately if you suspect your cat has consumed any part of this plant.

Q: Is St. John's Wort safe for dogs?

St. John's Wort is potentially toxic to dogs. The plant contains hypericin, which can cause increased sensitivity to light and skin inflammation. Seek veterinary care promptly if ingestion is observed or suspected.

Hypericum perforatum

Klamath Weed is a perennial flowering plant known for its bright yellow blooms and medicinal history, but it contains compounds that can cause significant health issues if ingested by pets. It is widely recognized as a toxic plant that requires careful management in households with animals.

Check a list

Common Saint John's WortGoatweedHypericum perforatumSt. John's Wort

Light: Full sun to partial shade
Habit: Upright, spreading perennial
Care: Low

Safety status

Cats & Dogs

Potentially toxic

Consulted references classify the plant as toxic or irritating for that pet type.

Verified against ASPCA/provenance audit 2026-05-06 on May 6, 2026.

Sources

ASPCA Toxic Plant List

If a pet has chewed or swallowed plant material and is showing symptoms, contact a veterinarian or poison resource immediately. This product is for structured reference, not diagnosis.

Cats — concern notes

Common signs

Photosensitivity, skin irritation, drooling, vomiting, and potential neurological changes.

Escalation note

Ingestion can lead to severe skin reactions when exposed to sunlight. Please contact your veterinarian immediately if you suspect your cat has consumed any part of this plant.

Dogs — concern notes

Common signs

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.

Safer alternatives

No hand-picked alternatives for this plant yet. You can still pick your own using the Compare button on any other plant.

Source evidence

ASPCA Toxic Plant List

toxicology · 99% reliability

Open source

St. John's Wort is listed as toxic to both cats and dogs due to the presence of hypericin.

NC State Extension Plant Toolbox

botanical · 94% reliability

Open source

Hypericum perforatum is a perennial herb that is considered toxic to livestock and pets.

cats safety page My cat ate St. John's Wort dogs safety page My dog ate St. John's Wort

Same safety verdict

Other plants with the same verdict

Spreading Dogbane

Apocynum androsaemifolium

Bitter Root is a perennial herbaceous plant known for its pink, bell-shaped flowers and milky sap. It contains cardiac glycosides that are harmful if ingested by pets.

Potentially toxic for cats & dogs.

Monstera

Monstera deliciosa

Monstera deliciosa is a popular tropical houseplant known for its large, fenestrated leaves and vining growth habit. It contains insoluble calcium oxalate crystals that can cause irritation if ingested by pets.

Potentially toxic for cats & dogs.

Snake Plant

Dracaena trifasciata

Dracaena trifasciata is a popular, hardy houseplant known for its stiff, sword-like leaves with striking yellow margins. It is widely appreciated for its air-purifying qualities and ability to thrive in various indoor conditions.

Potentially toxic for cats & dogs.

Philodendron

Philodendron spp.

Philodendrons are popular tropical foliage plants known for their lush, heart-shaped or split leaves. They contain insoluble calcium oxalate crystals that can cause irritation if ingested.

Potentially toxic for cats & dogs.

Same growing conditions

Plants for the same room

Meadow Buttercup

Ranunculus acris

Ranunculus acris is a perennial herbaceous plant known for its bright yellow flowers and presence in meadows. It contains compounds that can cause irritation upon contact or ingestion.

Potentially toxic for cats & dogs.

Orange Day Lily

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The Orange Day Lily is a perennial flowering plant known for its vibrant, trumpet-shaped blooms. While popular in gardens, it is highly dangerous to cats if ingested.

Potentially toxic for cats.

Uncertain for dogs.

Black Nightshade

Solanum nigrum

Black Nightshade is an herbaceous plant in the Solanaceae family containing solanine alkaloids that are harmful if ingested. It is widely considered a weed and is not typically cultivated as an indoor houseplant.

Potentially toxic for cats & dogs.

China Aster

Callistephus chinensis

China Aster is a popular annual flowering plant known for its daisy-like blooms and vibrant colors. It is considered non-toxic to household pets, though ingestion of large amounts of plant material may cause minor digestive discomfort.

Generally safe for cats & dogs.