First Walk is on Us!

✓ GPS tracked walks
✓ Activity reports
✓ On-demand walkers
Book FREE Walk

Jump to Section

What is Indian Paintbrush Poisoning?

Indian paintbrush flowers resemble paintbrushes dipped in bright red or orange paint. Indian paintbrush grows in the Western and Southwestern grasslands of the United States.  The Indian paintbrush can grow up to 3 feet tall. 

The plant receives its name from a Native American legend.  The legend tells the story of a young brave who received special paintbrushes from the Great Spirit.  Once the young brave painted his beautiful landscape he left the brushes in the field.  The paintbrushes spouted beautiful and bright flowers, thus the Indian paintbrush flowers.

If your horse is showing signs of Indian paintbrush poisoning he should be removed from the pasture he has been foraging in.  Please call an equine veterinarian as soon as possible. Indian paintbrush poisoning in horses can be fatal.

The biennial plant Indian paintbrush (prairie-fire) is capable of storing high levels of selenium, which is toxic if ingested by a horse. The scientific name for Indian paintbrush is Castilleja.

Book First Walk Free!

Symptoms of Indian Paintbrush Poisoning in Horses

Acute symptoms may include:

  • Difficulty breathing
  • Lethargy
  • Depression
  • Fear/nervousness
  • Diarrhea
  • Lack of appetite
  • Fever
  • Unsteady gait
  • Tachycardia
  • Teeth grinding
  • Incoordination
  • Fluids in the lungs
  • Damage to liver, kidneys and/or lungs

Chronic symptoms may include:

  • Dull hair coat
  • Anemia
  • Joint stiffness
  • Lameness
  • Weight loss
  • Hooves may have deformities, circular bumps
  • Loss of mane and tail hair

Causes of Indian Paintbrush Poisoning in Horses

Indian paintbrush poisoning in horses is caused by the ingestion of the plant.  The levels of the selenium can vary in plants from mild to severe. Horses typically do not eat Indian paintbrush plants; the plant is not palatable.  Unfortunately, if a horse is foraging in an overgrazed pasture, he will end up eating what plants he can find.

Diagnosis of Indian Paintbrush Poisoning in Horses

The veterinarian may want to see the pasture where your horse forages. The bright red flowers on the Indian paintbrush are easily spotted. He may want to see your horse walked on a lead, so he can observe the patient’s gait.  

Diagnostic tests that the veterinarian may recommend are a complete blood count (CBC), serum chemistry panel and a urinalysis, which may determine kidney and liver function. These blood tests can evaluate how the toxin is affecting the body’s organs.  The serum chemistry panel checks the electrolytes levels, blood protein and evaluates organ function. 

If the veterinarian suspects Indian paintbrush poisoning he will also test for selenium levels.  Selenium levels can be tested three different ways. Diagnostic evaluation of whole blood and serum, as well as hair analysis can indicate the levels.  Most veterinarians feel that whole blood is the most accurate way to check selenium levels. However, hair analysis can determine selenium concentrations that occurred months or years before the test was taken.

Treatment of Indian Paintbrush Poisoning in Horses

Treatment of Indian Paintbrush Poisoning in Horses

If the veterinarian diagnosed your horse with Indian paintbrush poisoning, he may start an intravenous line to help keep the horse hydrated. If he is not eating, your equine may need to be tube fed.  The veterinarian will stress that it is important that your horse is started on a high protein diet He may also want the patient to be on copper supplements and vitamins. 

If during the examination the veterinarian noted hoof lesions, he will refer you to a reputable farrier that can correct any hoof abnormalities. Your horse will need to be seen by a farrier who will work concurrently with the veterinarian on a regular basis to repair and maintain the hooves.

Recovery of Indian Paintbrush Poisoning in Horses

Once Indian paintbrush poisoning is treated, the recovery prognosis is good.  Follow up visits will be required to monitor the progress. The veterinarian may want to have the selenium level rechecked, to ensure that the levels are going down.  

The horse should not be allowed in the pasture until the Indian paintbrush plants are removed. The surrounding soil should be checked for selenium levels as should ponds and/or any other water source on the property.

The pasture needs to properly be maintained and fertilized, and toxic plants need to be removed.  Herbicides can help kill toxic weeds. A local agricultural extension agent can help you to identify toxic plants that can harm your horse. The agent may also help suggest nutritional grasses and legumes that should be introduced to  the pasture for the horse to forage on.