Toxic Plants
Becoming familiar with some of the most dangerous plants that are toxic for horses, can help to protect them.
Colorado is a fantastic place for horse owners and enthusiasts. However, as a horse owner/rider, it is important to know about common toxic plants found in our state. Several plants found in nature can cause your horse to get sick – some can even be deadly. While you try to watch what you feed your horses, it’s wise to also be aware of potential dangers in your pasture.
One way to protect your horse is to become familiar with some of the most dangerous plants that may be toxic for horses to eat.
**Note: The way your horse reacts to what they eat may vary, but the plants listed here have been proven to cause severe reactions. All treatments indicated should be performed by a veterinarian. If you suspect your horses has ingested one of these plants, contact your veterinarian right away.**
(Photo Credit: brewbooks, CC BY-SA 2.0 <https://creativecommons.org/licenses/by-sa/2.0>, via Wikimedia Commons)
Locoweed – Found with white or purple flowers
Symptoms: decreased appetite, signs neurological damage (stumbling, disorientation), unpredictable behavior, sudden change in demeanor, emaciation, reproductive dysfunction, and increased susception to disease
Treatment: Horses are often permanently affected, severity depends on the duration of locoweed consumption.
Hemlock
Symptoms: tremors, blocked spinal cord reflexes, paralysis, salivation, frequent urination, rapid/weak pulse, coma and sudden death from respiratory failure.
Treatment: No specific treatment, supportive therapy is recommended.
(Photo Credit: Djtanng, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons)
(Photo Credit: https://upload.wikimedia.org/wikipedia/commons/c/c3/Buttercups_%28%28Ranunculus_repens%29_-_geograph.org.uk_-_834285.jpg)
Buttercups
Symptoms: irritated tissues in the mouth and throat, affects the gastrointestinal system (colic, diarrhea), causes excessive salivation
Treatment: Horses usually recover rapidly when removed from the buttercups.
Pigweed
Symptoms: difficulty breathing, muscle weakness and muscle tremors, loss of coordination, diarrhea, reduced appetite, coma, possible renal and cardiac failure.
Treatment: There is no specific treatment except to provide supportive therapy.
(Photo Credit: F. D. Richards from Clinton, MI, CC BY-SA 2.0 <https://creativecommons.org/licenses/by-sa/2.0>, via Wikimedia Commons)
(Photo Credit: Stan Shebs, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons)
Sagewort/Fringed Sage
Symptoms: seem stressed and behave unpredictably. Falling down, circling, and walking into objects unexpectedly. Will have sage smell to breath and manure.
Treatment: Supportive therapy and stall rest. Horses often recover.
Tansy Ragwort
Symptoms: lethargic, abdomen fills with fluid, impaired vision, incessant stumbling, aimless wandering, signs of liver disease, weight loss, and death due to liver disease.
Treatment: Liver disease can be prevented if horses are removed from the plant in time. However, once liver disease does occur, there is not cure.
(Photo Credit: Ron Clausen, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons)
(Photo Credit: The original uploader was J.smith at English Wikipedia., CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons)
Russian Knapweed – Yellow Star Thistle
Symptoms: grinning appearance, chewing without swallowing, head tossing, difficulty breathing, submerging head in water, death due to dehydration or malnutrition.
Treatment: There is not a known cure.
Milkweed
Symptoms: colic, muscle tremors, seizures, coma, respiratory troubles, weakness, and death.
Treatment: If a lethal dose has not been consumed, horses can recover. Remove horse from the plant and provide fresh water, food, and shade.
(Photo Credit: Shadowmeld Photography, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons)
How to Prevent Poisoning
The first tip is simple – give your horse enough food. Making sure your horse isn’t hungry will help prevent grazing on dangerous plants in the wild. Many poisonous plants don’t taste good, so horses typically need to be hungry to eat them.
According to the AAEP, making sure your horse is fed enough nutritious food will cut back on them wanting to eat toxic plants.
Second, be careful what is inside the feed you do give your horse. Owners may accidentally feed horses contaminated hay or grain by offering certain tree and bush clippings. Leaves and clippings from toxic plants/trees can end up in hay or grain.
When to Seek Help
If you notice your animal acting strange, or have suspicion they may have consumed one of these dangerous plants, it is best to veterinary help right away. Depending on the amount eaten and the type of plant, there may be treatment available.
Sources:
AAEP – https://aaep.org/issue/panic-or-procrastinate-what-do-if-your-horse-has-eaten-poisonous-plant
ASPCA – https://www.aspca.org/pet-care/animal-poison-control/horse-plant-list
Penn State – https://extension.psu.edu/plants-toxic-to-horses
USDA – https://www.ars.usda.gov/
Colorado State – https://csuvth.colostate.edu/poisonous_plants/
