Can they eat it? / Tomato and potato plants (and green potatoes)
Can horses eat tomato and potato plants (and green potatoes)?
No. Nightshade family; the plants and green or sprouting tubers are toxic.
A ripe tomato or a cooked potato is low risk; the vines, leaves and green tubers are the problem, so keep garden waste out of reach.
Colic, drooling, weakness, dilated pupils.
Call your vet now. Note what was eaten, how much and when; do not wait for signs.
Why it is dangerous
Tomato and potato plants belong to the nightshade family and contain glycoalkaloids, including solanine and tomatine, which interfere with the nervous system and irritate the gut. The vines, leaves, stems and green or sprouting potato tubers carry the highest concentrations. Clippings tossed on a compost pile or a fence line are a common way horses get into trouble, and wilted leaves can be just as dangerous as fresh ones.
How much is too much
For a 1,000 lb horse there is no safe amount of the leaves, vines or green tubers, so a mouthful is a reason to call the vet. A ripe tomato or a cooked potato offered as a treat is low risk, though a few slices is plenty. Ponies, miniatures and horses with metabolic issues are more vulnerable because of their smaller body weight and sensitive systems, so treat any plant exposure in them as urgent.
Horses
For full-size horses in work or at pasture, keep garden clippings, pulled vines and compost well away from the paddock and feed room. Horses turned out near a vegetable patch may sample leaves over a fence. Check fencelines after weeding, and make sure hay and bedding do not contain nightshade clippings that might have been baled in by mistake.
Ponies and easy keepers
Ponies, miniatures, seniors and easy keepers can react to smaller amounts and may show symptoms faster. Be especially careful with garden trimmings near any stall or small paddock. Because these animals are often kept in tighter spaces, remove all nightshade plants from their reach entirely and never offer green potato peels or sprouted tubers as treats.
Safe alternatives
Offer a few apple slices, a handful of carrot coins or a small scoop of plain pelleted feed as treats. Cut them into bite-size pieces and serve them in a bucket or flat hand so they are easy to chew. Keep a bowl of fresh hay or grass within reach to satisfy foraging.
Questions people ask
Can horses eat tomato plant leaves in hay?
No. Nightshade leaves and vines can end up in hay or bedding and are toxic. Inspect hay before feeding and call your vet if you see any tomato or potato foliage.
My horse ate some potato peelings. What should I do?
Call your vet right away, even if your horse looks fine. Note what was eaten, how much and when, and do not wait for signs such as colic or drooling.
Are tomatoes safe for horses in competition?
Check your show's rules before offering any treats. Many organizations restrict feed and treats in the ring, and a ripe tomato is generally better kept at home.
Toxic for horses means: do not give it; if they ate it, call your vet or a poison line.
General information from veterinary guidance, not a diagnosis. If you are worried, call your vet or a pet poison line: ASPCA Animal Poison Control (888) 426-4435. Charges may apply.
Written by Hoofdeck editors · updated Nov 13, 2026 · from ASPCA Animal Poison Control, Merck Veterinary Manual and university extension guidance.