Safety verdict
Consulted references classify the plant as toxic or irritating for that pet type.
Pet ingestion lookup
My cat ate Poison Hemlock - what should I do?
Conium maculatum
Potentially toxic
Contact your veterinarian or an animal poison-control resource now, especially if any amount was chewed or swallowed.
Verified against ASPCA/provenance audit 2026-05-06 on May 6, 2026.
Signs to watch for
Tremors, salivation, dilated pupils, respiratory distress, and potential paralysis.
Escalation note
This plant is extremely toxic; ingestion of even small amounts can be fatal. Seek immediate veterinary emergency care if ingestion is suspected.
What to watch for
Early: drooling, agitation or restlessness, dilated pupils, and tremors. Following: vomiting and diarrhea, weakness, ataxia (a wobbly, drunken gait). Severe: muscle paralysis, respiratory distress, collapse, and death. Cats hide illness, so any combination of trembling, drooling, and weakness after suspected exposure should be treated as serious.
Time window
ASPCA doesn’t list a specific window. The toxic alkaloids act on the nervous system rapidly; in published case reports, signs commonly appear within minutes to a couple of hours of ingestion and can progress to respiratory paralysis within hours.
When to call the vet
Call immediately. Any suspected ingestion of poison hemlock by a cat is an emergency — contact your nearest emergency veterinary clinic right away, and call ASPCA Animal Poison Control at (888) 426-4435 en route. Bring a piece of the plant if you can do so safely.
What this means for your cat
For cats, poison hemlock is a true emergency, not a stomach ache. ASPCA lists it as toxic to cats with neurotoxic alkaloids that can cause paralysis and death. Even a small chewed leaf or stem warrants an immediate call to a vet or animal poison control — do not wait to see how things develop.
Sources: ASPCA (no first-aid guidance).
Source references
Poison-control resources
This page summarizes source-bound plant-safety information and is not veterinary advice.