Cow Parsnip — (c) Connie Taylor, some rights reserved (CC BY), uploaded by Connie Taylor
Photo by (c) Connie Taylor, some rights reserved (CC BY), uploaded by Connie TayloriNaturalistCC BY
cat safety reference

Is Cow Parsnip safe for cats?

Heracleum maximum

Cow parsnip is a large, herbaceous perennial member of the carrot family known for its tall stature and umbrella-like flower clusters. It contains furanocoumarins that can cause significant skin and mucosal irritation upon contact.

American cow parsnipCow parsnipHeracleum lanatumHeracleum maximum
Light
Partial shade to full sun
Habit
Herbaceous perennial
Care
Low

Safety status

Cats

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.

What this means for your cat

Cats — toxic. ASPCA classifies cow parsnip as toxic to cats; the furanocoumarins in the foliage cause phytophotodermatitis, a sun-triggered chemical burn that flares wherever sap touches skin or fur. Cats that brush past stems and then groom themselves can spread the sap across paws, muzzle, and ears.

What to watch for

Mouth and tongue irritation if leaves were chewed; redness, blistering, or hair loss on areas the sap contacted (often muzzle, paws, and ears); pawing at the face; squinting or eye irritation. Skin reactions worsen sharply once the cat goes into sunlight.

Time window

Skin reactions appear once the contact area meets UV light — usually within 24–48 hours of exposure — and can take days to a week or more to resolve. Oral irritation typically settles within a day if the cat stops chewing.

When to call the vet

Call any time you see blistering, raw skin, eye irritation, persistent drooling, or refusal to eat. Cats are small and skin reactions can become severe with normal sun exposure, so don't wait to see if it worsens.

First aid at home

Move the cat indoors and out of direct sunlight. With gloves on, wipe sap off the fur with a damp cloth and rinse the mouth gently with cool water if the cat will tolerate it. Do not induce vomiting. Then call your vet or ASPCA Animal Poison Control at (888) 426-4435.

Sources: ASPCA.

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.

Catsconcern notes

Common signs

Dermatitis, blistering, redness, and irritation of the mouth or throat if ingested.

Escalation note

The plant contains photosensitizing compounds that can cause severe skin reactions when exposed to sunlight. Please contact your veterinarian if you suspect ingestion or skin contact.

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

NC State Extension Plant Toolbox

botanical · 94% reliability

Open source

Heracleum maximum is a native perennial that can cause skin irritation in humans and animals due to furanocoumarins.

Cats & dogs pagedogs pageMy cat ate Cow Parsnip

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