Keeping your pet safe from harmful food or plants is an important part in every pet care routine.
Although having no poisonous plants in the pasture is ideal for horse owners, Dr. Leslie Easterwood, clinical assistant professor at the Texas A&M College of Veterinary Medicine & Biomedical Sciences said, horses typically do not eat toxic plants because they are not as appealing as forage. If plenty of tasty forage is available, horses are less likely to chow down on a toxic plant.
“There are some toxic plants that can seem particularly appealing to horses, but generally they will avoid toxic plants.”
This may be good news for horse owners, but it does not necessarily mean unkempt pastures are safe. “Generally, it is never good to allow toxic plants to be where horses have access to them,” Easterwood said. “There are always a few plants out there that could cause a problem if eaten by a horse.”
There are several plants in Arizona that are toxic to horses including Rayless Goldenrod, White Snake Root and Silverleaf Nightshade. Silverleaf Nightshade has beautifully scallop-edged elongated oval leaves in a sort of dusty-green color. The gorgeous purple flower opens to reveal bright yellow tubules (stamens).
The toxic agent is called solanine and is contained in both the leaves and the fruit (tiny round yellow berries) at all stages of maturity, but the ripe fruits are the most toxic.
The toxin affects horses, sheep, cattle and humans. Goats seem to be resistant. In controlled experiments performed by Texas A&M University, goats were not poisoned by the plants. These results would suggest that mixing goats in with other livestock may be beneficial to your overall pasture maintenance.
Horse owners should take time to look around their pastures and know what plants are growing. Additionally, Easterwood recommended mowing, shredding, and using chemical weed control to control toxic plants in the pasture.
“Horse owners can also arrange to meet with their county extension agent to have them come out and look at the plants in the pasture,” Easterwood said. “They are trained to spot the problem plants.”
Signs that a horse has eaten a poisonous plant include diarrhea, colic, neurologic conditions, such as seizures, and possibly even death. Although the effects of eating a poisonous plant can be serious, horses that are getting their nutrients from forage are not likely to choose a bitter, poisonous plant for dessert. Additionally, because of their size, horses have to consume higher quantities of a toxin to feel any effects. A general rule is if your pasture does not contain toxic plants and your horse is healthy, you have little to worry about. However, horse owners are encouraged to contact their veterinarian immediately if they are concerned their horse has ingested a poisonous plant.
Taking the extra step to keep your pasture clean and free of toxic plants can help keep your horse healthy. County extension agents are also excellent resources to learn more about toxic plants and how to eliminate them. Overall, removing any toxic plants from your horse’s environment is key in protecting their health.
Pet Talk is a service of the College of Veterinary Medicine & Biomedical Sciences, Texas A&M University. Stories can be viewed on the Web at vetmed.tamu.edu/pet-talk. Suggestions for future topics may be directed to [email protected] .
