You know that your horse has just ingested a poisonous plant, or a plant that you believe may be poisonous to horses.

Generally, horses are very good at avoiding toxic plants because they tend to be bitter and unpalatable. Horses usually do not consume enough of these plants to cause a problem, as long as they have plenty of hay or forage available. But under some circumstances, a horse will snatch a plant while tied or ridden. There are a small number of toxic plants that can cause harmful effects in just a few mouthfuls.

YOUR ROLE

First (being careful to avoid being bitten) pull whatever plant material you can out of your horse's mouth, and then wash your hands. If possible, wear gloves. Save the plant in a bag.

Contact your vet immediately and explain what happened. Place your horse in a stall and let them rest quietly until your vet arrives. Offer them some of their usual hay. Unlike many other animals, horses cannot vomit so drugs that induce vomiting (emetics) are useless in this circumstance.

Second, send your vet (via email or phone) a photo of the plant your horse ate for identification.

Other helpful information to provide:

Try to estimate how much of this plant was consumed, and whether your horse ate the leaves, stems, bark, roots, berries or fruit of a poisonous plant because the toxins often reside at different strengths within each of these parts of a plant. It's also important to know whether the plant ingested was fresh or dried. Some plants are more poisonous when fresh, and some plants are more poisonous after they have dried out.

You can also call the American Society for the Prevention of Cruelty to Animals (ASPCA) 24-Hour Animal Poison Control Center hotline at 888-426-4435. They even have a scale to assess the severity of poisoning based on animal's weight and presumed amount of toxin consumed. A consultation fee may apply.

To monitor the horse's health, perform the Whole Horse Exam, paying special attention to gum color, heart rate, attitude and appetite.

YOUR VET'S ROLE

If your vet is able to examine your horse promptly (within an hour of eating the toxic plant), they may try to remove some of it from your horse's stomach with a nasogastric tube. They may also give your horse laxatives or toxin binders to reduce the absorption of toxins. In most cases, the toxins in plants do not have a direct antidote. Most of the treatment is supportive nursing care.