Common equine poisons

If you think your horse, pony or donkey has been poisoned, contact your vet immediately.


Ragwort (Senicio Jacobae)

All parts of the plant are poisonous. Ragwort is said to be unappetising to horses and is usually only eaten when there is little choice of other plants. Dried ragwort remains toxic, but seems more appealing to horses.


Phenoxy acid herbicides

Phenoxy acid herbicides are a type of weed killer used on garden lawns. Other types of weed killer may also be toxic to horses. Poisoning occurs when recently treated plants are eaten.


Rodent poisons (‘rodenticides’)

The following specifically refers to anticoagulant rodenticides. Other types of rodenticide may also be poisonous to horses . Anticoagulants act by preventing blood clotting.  The baits are usually coloured blue or green (sometimes purple or red) and can be sold in the form of a powder, paste, seeds or grains.


Most horses will require a course of the antidote. Blood tests may confirm poisoning.


Yew tree (Taxus baccata)

All parts of the yew tree, apart from the fleshy fruit, are poisonous to animals (including the seeds within the fleshy fruit). Poisoning can occur all year round and even dried material can be toxic.


Signs may develop rapidly, and sudden deaths can occur.


Leyland Cypress (Cupressocyparis leylandii)

All parts of this plant are potentially toxic.


Oak (Quercus spp)

Oak poisoning usually occurs in either the spring (from eating young shoots) or in the autumn (after eating acorns and fallen leaves).


Read our top tips for more information on what to do if you think your horse, pony or donkey has been poisoned: Poisoning in equines.


Acknowledgement for this information is made to The Veterinary Poisons Information Service (VPIS).