Is Comfrey Toxic to Dogs?

☠️ ToxicSeverity: Moderate

✅ 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.

Yes, comfrey is toxic to dogs. One meal brings vomiting and diarrhea, and repeated grazing can cause progressive liver damage.

Also known as: Knitbone, Boneset, Symphytum officinale · Symphytum officinale

What makes it toxic

Pyrrolizidine alkaloids concentrated in leaves and especially roots. Acute effects are gut irritation; chronic effects are hepatotoxicity from alkaloid accumulation.

Warning signs to watch for

Acute: vomiting, diarrhea, drooling. With repeated exposure: weight loss, poor appetite, jaundice, fluid build-up and other signs of liver failure.

What to do if your dog eats it

Offer water and call your vet after a substantial ingestion. If your dog has eaten comfrey more than once, ask your vet about liver enzyme testing.

Common questions

Why is comfrey still sold if it is toxic?

Topical use on intact human skin is the traditional use, and refined products limit alkaloid content. None of that makes the raw plant safe for a dog to eat.

Is the root more dangerous than the leaves?

Yes — roots carry the highest alkaloid concentration. A dog that digs up and chews comfrey roots got the worst part of the plant.

More plants checked for dogs

Pothos☠️ ToxicYes, pothos is toxic to dogs. Chewing any part of the vine releases calcium oxalate crystals tha Aloe Vera⚠️ Mildly ToxicAloe vera is mildly to moderately toxic to dogs. The skin and latex layer of the leaf contain co Spider Plant✅ Non-ToxicNo, spider plants are non-toxic to dogs. A dog that nibbles the arching leaves is not at risk of Easter Lily⚠️ Mildly ToxicEaster lilies are only mildly toxic to dogs — they usually cause stomach upset, not the fatal ki Sago Palm☠️ ToxicYes — sago palm is severely toxic to dogs, with a documented fatality rate around 50% when untre Boston Fern✅ Non-ToxicNo, Boston ferns are non-toxic to dogs. Chewing a frond will not poison your dog.

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.