Are Holly and Mistletoe Poisonous to Cats and Dogs?
Quick answer
Yes, both are on the ASPCA toxic plant list for dogs, cats and horses. Pet Poison Helpline says most pets that chew them get stomach upset, and that serious effects from mistletoe are rare and linked to large amounts. Of the other Christmas plants, the amaryllis bulb is the one it singles out. If your pet has eaten any of these and seems unwell, phone your vet.
Taken from this page and its sources. Not veterinary advice. If your pet has already eaten some and seems unwell, see who to call.
Holly
The ASPCA lists English holly as toxic to dogs, cats and horses, names saponins as the cause, and lists vomiting, diarrhoea and depression as the signs. It also says the leaves and berries are of low toxicity. Pet Poison Helpline says all parts of the plant can cause stomach upset, with vomiting, diarrhoea, drooling and lethargy. The spiky leaves can also hurt a mouth on their own. Sources: ASPCA Animal Poison Control, English holly; Pet Poison Helpline, Deck the halls with holiday plants: but are they toxic? (Charlotte Flint, DVM).
Mistletoe
The ASPCA lists American mistletoe as toxic to dogs, cats and horses, with vomiting and diarrhoea, and less often difficulty breathing, a slow heart rate and, rarely, low blood pressure. Pet Poison Helpline says small amounts usually cause mild vomiting, nausea and diarrhoea, and that the heart and nervous system effects seen with large amounts are rare in pets. It also points out that shop-bought mistletoe often has plastic berries, which could block the gut if swallowed. Sources: ASPCA Animal Poison Control, Mistletoe "American"; Pet Poison Helpline, Deck the halls with holiday plants: but are they toxic? (Charlotte Flint, DVM).
Amaryllis
Pet Poison Helpline says amaryllis flowers and leaves can cause vomiting, drooling and diarrhoea, and that the bulb is more toxic: eaten in larger amounts it can possibly cause weakness, tremors, seizures and changes in blood pressure. Bulbs sold boxed as Christmas presents sit within reach until they are planted. Source: Pet Poison Helpline, Deck the halls with holiday plants: but are they toxic? (Charlotte Flint, DVM).
Christmas cactus
Pet Poison Helpline considers Christmas cactus non-toxic: it may cause mild vomiting, nausea or diarrhoea, but says serious toxicity is not expected. Source: Pet Poison Helpline, Deck the halls with holiday plants: but are they toxic? (Charlotte Flint, DVM).
At home
- Hang mistletoe high, and sweep up any berries, real or plastic, that drop.
- Keep holly wreaths and table decorations out of reach, and check wreaths on doors at dog height.
- Keep amaryllis bulbs boxed and out of reach until they are planted.
Sources
- ASPCA Animal Poison Control, English holly, read 7 November 2026.
- ASPCA Animal Poison Control, Mistletoe "American", read 7 November 2026.
- Pet Poison Helpline, Deck the halls with holiday plants: but are they toxic? (Charlotte Flint, DVM), read 7 November 2026.
Sources last checked 7 November 2026. Spotted something out of date? Tell us.
Related pages
Are poinsettias poisonous to pets?, Christmas trees, lilies and cats and Christmas pet safety.
