Say ‘No’ to Nightshade

Safe Guard Your Horse Safe from a Poisonous Plant Family

by Eleanor Blazer


Photo credit Eleanor Blazer

You say “potato,” I say, “poison;” you say “tomato,” I say “toxin.” These plants are members of the nightshade (solanaccae) family and include eggplant, tobacco, chili and bell peppers, horse nettle, and jimsonweed. There are more than 2,000 plants in this family: All are poisonous to horses. The poison is an alkaloid. It’s highly concentrated in the greenery and unripe fruit, but is present in all parts of the plant. The toxin affects the nervous and digestive system. Symptoms of poisoning can be depression preceded by nervousness, low heart and respiration rate, colic, muscle twitching and/or weakness, eye problems (light sensitivity, blindness, dilated pupils), excessive salivation, inability to stand and bowel movement changes (diarrhea or constipation).

Horses can be poisoned by nightshade by inadvertent contamination of feeds.  For example, nightshade is harvested along with the desirable grain. Horses have also been poisoned when fed potatoes and tomatoes. Under ideal circumstances horses will rarely eat nightshade as it doesn’t taste good. If it is baled in hay they will sort it out and leave it. Hungry horses will eat nightshade if there is no other feed available.

Horses can recover from alkaloid poisoning if it is caught and identified in time. There is no specific diagnostic test to determine if the symptoms are being caused by nightshade. Blood work and a urinalysis will aid the vet in diagnosis. Examination of fecal matter to detect plant residue can help, but this is usually done after the horse has died.

Horse owners are urged to research the types of nightshade that grow in their area and learn to identify them. 

Nightshade can be hard to eradicate and aggressive chemical control is the most successful method of removal. Preventing nightshade from invading land by not overgrazing, fertilizing and maintaining healthy forage is the best form of management. 


For information about caring for and feeding horses take the online courses “Stable Management” and “Nutrition for Performance Horses” taught by Eleanor Blazer. Earn certification or work toward a Bachelor of Science degree in equine studies. Go to www.horsecoursesonline.com for more information. Visit Eleanor’s web site at www.thewayofhorses.com.


Published June 2013 Issue

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