Dreamcatcher Alpacas
Plant safety · Toxic

Is St. John's Wort Poisonous to Alpacas?

St. John's Wort (Hypericum perforatum) — a weed. Here is what alpaca owners need to know.

Updated 2026-10-02By the Dreamcatcher Alpacas editorial team
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Yes — St. John's wort is toxic to alpacas.

Keep it out of pastures, hay and reach of fences, and never feed trimmings.

St. John's Wort (Hypericum perforatum)
St. John's Wort (Hypericum perforatum). Photo: Didier Descouens, CC BY-SA 4.0 via Wikimedia Commons.
Status
Toxic
Scientific name
Hypericum perforatum
Family
Hypericaceae
Plant type
Weed
Also known as
Klamath weed, Goatweed, St John's wort, perforate St John's-wort, common St. Johnswort
Toxic parts
Flowering tops; remains active in hay
Toxic compound
Hypericin (photodynamic pigment)

Why it matters

Causes primary photosensitization. Alpacas with white or light-colored faces and freshly shorn skin are most affected. Remove from pasture and hay fields.

Signs of St. John's wort poisoning in alpacas

  • Reddened, swollen, peeling skin on unpigmented or lightly fleeced areas (face, ears, legs)
  • Itching and head rubbing
  • Seeking shade
  • Eye irritation and tearing

Signs can appear within minutes (cyanide, cardiac toxins) or only after weeks of exposure (liver toxins). Many poisoned camelids are simply found dead, so prevention is everything.

What to do if your alpaca ate St. John's wort

  1. Move the herd away and remove any remaining plant material, clippings or fallen leaves.
  2. Call your veterinarian immediately, even if the alpaca looks normal. Say what was eaten, roughly how much and when.
  3. Bring a sample or clear photo of the plant to help identification.
  4. Do not give home remedies, oils or try to make the alpaca vomit unless your vet tells you to.
  5. Keep the animal quiet, in shade or shelter, with water available. Write down the time and every symptom you see.
  6. Check every other alpaca that had access, then remove the plant permanently (including roots).

Emergency: call your veterinarian immediately. If you cannot reach them, contact an animal poison control service (in the U.S., the ASPCA Animal Poison Control Center or Pet Poison Helpline; fees may apply). Bring a sample or photo of the plant.

About the plant

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.From Wikipedia — “Hypericum perforatum”, licensed under CC BY-SA 4.0.

Where it grows

GBIF, the Global Biodiversity Information Facility, holds 931,631 recorded observations of Hypericum perforatum L. worldwide, including 25,057 in the United States. It belongs to the Hypericaceae family. See the occurrence map on GBIF.

Frequently asked questions

Is St. John's wort poisonous to alpacas?
Yes. Yes — St. John's wort is toxic to alpacas. Causes primary photosensitization. Alpacas with white or light-colored faces and freshly shorn skin are most affected. Remove from pasture and hay fields.
What part of St. John's wort is toxic to alpacas?
Flowering tops; remains active in hay.
What are the symptoms of St. John's wort poisoning?
Reddened, swollen, peeling skin on unpigmented or lightly fleeced areas (face, ears, legs), itching and head rubbing, seeking shade and eye irritation and tearing.
Is dried St. John's wort safe?
No — the toxin in this plant remains active when dried, so contaminated hay and dried clippings are still dangerous.

Keeping pastures safe

  • Walk every paddock and fence line each season and remove toxic plants, including roots.
  • Never throw garden, hedge or lawn clippings over the fence.
  • Check pastures after storms for fallen branches (cherry, red maple).
  • Buy hay from known sources and inspect it for weeds.
  • Keep pastures well managed — hungry alpacas eat plants they would normally avoid.

Browse the full toxic plant checker, the printable list of poisonous plants and the list of safe plants.

This page is educational and does not replace advice from a veterinarian who has examined your animals. Camelid medicine uses many drugs “extra-label”, so dosing must come from your vet. In an emergency, call your vet first. Read our disclaimer · How we write and review content.

Data: plant status compiled from veterinary toxicology references (see sources); taxonomy and occurrences from GBIF; identifiers from Wikidata Q158289.