Pet safety
Is Square-stalked St John's-worttoxic to cats & dogs?
Hypericum tetrapterum
Toxic
Quick verdict — at a glance
- Toxic to cats?
- Yes — toxic
- Toxic to dogs?
- Yes — toxic
- ASPCA classification
- Toxic to pets · botanical name Hypericum tetrapterum
Is square-stalked st john's-wort safe for cats and dogs?
Avoid for a pet household. Square-stalked St John's-wort is ASPCA-listed toxic to both cats and dogs; even a small chew can drive a vet visit. Plenty of look-alikes on the non-toxic side of the list — see alternatives below. This classification follows the ASPCA Toxic and Non-Toxic Plant List, the most widely used reference for companion-animal plant safety in the US and the standard most UK vets cite as well. As a Hypericum species, it contains hypericin, the toxic principle identified by the ASPCA in St John's Wort (H. perforatum), which is listed as toxic to dogs, cats, and horses. Clinical signs include photosensitization and ulcerative dermatitis. The RHS also notes the fruits are not for consumption and recommends caution when handling. Treat as toxic to companion animals and keep pets away from the plant.
| Pet | Toxic? | Per ASPCA |
|---|---|---|
| Cats | Yes | Toxic to pets |
| Dogs | Yes | Toxic to pets |
What happens if a pet eats square-stalked st john's-wort?
As a Hypericum species, it contains hypericin, the toxic principle identified by the ASPCA in St John's Wort (H. perforatum), which is listed as toxic to dogs, cats, and horses. Clinical signs include photosensitization and ulcerative dermatitis. The RHS also notes the fruits are not for consumption and recommends caution when handling. Treat as toxic to companion animals and keep pets away from the plant. Signs usually appear soon after chewing rather than hours later. If you see drooling, pawing at the mouth, head-shaking, vomiting, loss of appetite, or unusual lethargy after your pet has had access to square-stalked st john's-wort, treat it as a suspected ingestion and act on the steps below.
What to do if your pet ate square-stalked st john's-wort
- Remove any plant material from your pet's mouth and move square-stalked st john's-wort out of reach.
- Note how much was eaten and when, and watch for drooling, vomiting, or lethargy.
- Do not induce vomiting unless a vet or poison-control specialist instructs you to.
- Call your vet or the ASPCA Animal Poison Control Center on (888) 426-4435 and follow their advice.
- Bring a leaf or photo of square-stalked st john's-wort to the appointment so it can be treated correctly.
This page is general guidance, not veterinary advice. Pets vary, and a reaction may be to soil, fertiliser, or pesticide rather than the plant. If you are worried, always contact a vet or the ASPCA Animal Poison Control Center on (888) 426-4435 — do not wait for symptoms to worsen.
Pet-safe alternatives to square-stalked st john's-wort
Want the same look without the risk? These plants are listed as non-toxic to cats and dogs by the ASPCA and have similar care needs:
- Hoya — non-toxic to cats and dogs (care guide)
- Bromeliad — non-toxic to cats and dogs (care guide)
- Christmas cactus — non-toxic to cats and dogs (care guide)
- African violet — non-toxic to cats and dogs (care guide)
Square-stalked St John's-wort and pets — frequently asked questions
Is square-stalked st john's-wort toxic to cats?
Square-stalked St John's-wort (Hypericum tetrapterum) is toxic to cats according to the ASPCA. As a Hypericum species, it contains hypericin, the toxic principle identified by the ASPCA in St John's Wort (H. perforatum), which is listed as toxic to dogs, cats, and horses. Clinical signs include photosensitization and ulcerative dermatitis. The RHS also notes the fruits are not for consumption and recommends caution when handling. Treat as toxic to companion animals and keep pets away from the plant. Keep it out of reach and contact your vet or the ASPCA Animal Poison Control Center on (888) 426-4435 if your cat chews it.
Is square-stalked st john's-wort toxic to dogs?
Per the ASPCA, Square-stalked St John's-wort (Hypericum tetrapterum) is toxic to dogs. Dogs often chew more enthusiastically than cats, so a toxic plant like square-stalked st john's-wort is best removed from the floor and low shelves entirely.
What happens if my pet eats square-stalked st john's-wort?
As a Hypericum species, it contains hypericin, the toxic principle identified by the ASPCA in St John's Wort (H. perforatum), which is listed as toxic to dogs, cats, and horses. Clinical signs include photosensitization and ulcerative dermatitis. The RHS also notes the fruits are not for consumption and recommends caution when handling. Treat as toxic to companion animals and keep pets away from the plant. Signs usually appear soon after chewing rather than hours later. If you see drooling, pawing at the mouth, head-shaking, vomiting, loss of appetite, or unusual lethargy after your pet has had access to square-stalked st john's-wort, treat it as a suspected ingestion and act on the steps below.
What should I do if my cat or dog ate square-stalked st john's-wort?
Stay calm. Remove any remaining plant material from your pet's mouth and take the plant away so they cannot eat more. Note roughly how much was eaten and when. Do not make your pet vomit unless a vet or poison-control specialist tells you to. Call your vet or the ASPCA Animal Poison Control Center on (888) 426-4435 (a consultation fee may apply) and follow their advice. Bringing a photo or a leaf of square-stalked st john's-wort to the appointment helps the vet treat it correctly.
What are pet-safe alternatives to square-stalked st john's-wort?
If you want a similar look without the risk, good non-toxic swaps include hoya, bromeliad, christmas cactus, african violet. All of these are listed as non-toxic to cats and dogs by the ASPCA, so they suit a home where pets have access to your plants.
Full square-stalked st john's-wort care
Pet-safety is one piece of the picture. For light, watering, soil, and troubleshooting, see the complete square-stalked st john's-wort care guide, or browse the full pet-safe plant library to check another plant before you buy it.