EPM or Laminitis


Equine Protozoal Myeloencephalitis (EPM) is a neurological disease in horses caused by a protozoan parasite. The symptoms can be subtle and may mimic other conditions.

Symptoms of EPM:

  1. Incoordination: Horses may show signs of weakness, stumbling, or difficulty walking.
  2. Muscle Atrophy: Loss of muscle mass, especially along the topline and hindquarters.
  3. Abnormal Gaits: Unusual movements such as dragging toes, crossing legs, or tripping.
  4. Facial Paralysis: Drooping of the face or difficulty swallowing.


Laminitis in horses is a condition affecting the hooves, particularly the sensitive laminae, which connect the hoof wall to the coffin bone inside. Laminitis and EPM (Equine Protozoal Myeloencephalitis) are distinct conditions, but they can share some similarities in symptoms, leading to potential confusion. 

Early Symptoms of Laminitis:

  1. Hoof Pain: Your horse may show signs of discomfort in its hooves, especially when walking on hard surfaces.
  2. Reluctance to Move: Laminitis can make a horse hesitant to move or walk, as the pain in the hooves worsens with activity.
  3. Increased Heart Rate: Horses with laminitis might have an elevated heart rate due to the pain and stress.

Similarities with EPM:

  1. Gait Abnormalities: Both conditions can cause changes in the horse's gait. Laminitis may result in a hesitant, stilted walk similar to the unsteady gait seen in EPM.
  2. Reluctance to Move: Horses with EPM may also be reluctant to move due to neurological issues, creating a similarity with laminitis.

Neurological issues in horses can arise from various causes, including infections, injuries, and metabolic disorders. The broad range of potential causes makes it necessary to conduct thorough diagnostic tests to pinpoint the exact reason for the symptoms.

Other Conditions Often Misdiagnosed as EPM:

  1. Vitamin E Deficiency: Similar neurological signs may be seen with low vitamin E levels.
  2. Lyme Disease: Tick-borne illness can cause neurological symptoms in horses.
  3. Equine Herpesvirus: Neurological forms of the virus may be mistaken for EPM.

Always consult with a veterinarian for accurate diagnosis and appropriate treatment options tailored to your horse's specific needs.

Reasons to Take Action:

  1. Early Treatment is Key: Prompt intervention can improve the chances of recovery.
  2. Progressive Disease: EPM can worsen over time, affecting the spinal cord and brain.
  3. Prevent Further Damage: Timely treatment can help prevent permanent neurological damage.

Available Medications:

  1. Antiprotozoal Drugs: Marquis (ponazuril) and Navigator (nitazoxanide) are commonly used.
  2. Anti-Inflammatory Medications: Corticosteroids may be prescribed to reduce inflammation.
  3. Supportive Care: Nutritional supplements and physical therapy may aid recovery.


To address these challenges and needs, horse owners and veterinarians should collaborate closely, communicate effectively, and pursue thorough diagnostic evaluations. Utilizing advanced diagnostic tools and seeking input from specialists can improve the accuracy of the diagnosis and help differentiate EPM from other conditions with similar symptoms. Early action remains crucial, but it must be accompanied by a careful and comprehensive diagnostic approach to avoid misdiagnosis.