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Is Hyssop Toxic to Cats?

⚠️ Mildly ToxicSeverity: Mild
✅ Cross-checked against veterinary poison-control guidance · Oct 2026 audit
⚠️ Educational info only. If your pet just chewed something and looks unwell, skip the reading and call your vet or Pet Poison Helpline (US): (855) 764-7661.
Hyssop is mildly toxic to cats. Chewing the aromatic herb can cause vomiting and diarrhea, and large amounts stress the nervous system.

Also known as: Garden Hyssop, Hyssopus officinalis · Hyssopus officinalis

What makes it toxic

Essential oils rich in pinocamphone and related ketones, which irritate the gut and, in significant doses, affect the nervous system.

Warning signs to watch for

Drooling, vomiting, diarrhea and mild lethargy within hours; very large amounts could add tremors or restlessness.

What to do if your cat eats it

Remove plant material, offer water and monitor. Call your vet if vomiting persists, and go in promptly if tremors or wobbliness appear.

Common questions

Is anise hyssop as risky as true hyssop?

Anise hyssop (Agastache) is a different, milder plant generally considered safer. The pinocamphone concern applies to true Hyssopus officinalis.

Can cats have hyssop tea?

Not deliberately. The concentrated oils in a brewed tea are exactly what a cat processes poorly.

More plants checked for cats

This page is general educational information, not a substitute for professional veterinary advice. Every pet is different — if your animal ate something concerning, contact your veterinarian or a pet poison hotline right away. Checking what your pet can eat? Visit our sister site SafeOrToxic.