Side view of horse's head

Neurological Health

Treat with Confidence

Equine Nervous System

 

The horse’s nervous system consists of the brain, brainstem, spinal cord and peripheral nerves. Each part of the nervous system controls a specific job such as behavior, reflexes, and coordination of movement. The clinical signs of neurologic diseases depend on which part of the nervous system is affected. The disorders are serious and often can be debilitating. 

 

Possible causes of equine neurological diseases include developmental problems, trauma, degenerative conditions, and infectious diseases. One of the most common equine central nervous system disorders is equine protozoal myeloencephalitis (EPM). This serious disease is most commonly caused by the parasite Sarcocystis neurona that invades the brain and spinal cord. The infective stage of the parasite (the sporocysts) is passed in the opossum's feces. Opossums are definitive hosts for this parasite and horses become infected through contact with the feces by grazing or by eating contaminated feed. The ingested sporocysts migrate from the intestinal tract into the bloodstream and cross the blood-brain barrier then begin to attack the horse's central nervous system.

 

More than 70 percent of all horses in the United States may have been exposed to the organism at some point in their lives but only approximately one percent of exposed horses develop the clinical disease.2 EPM can be difficult to diagnose because its signs often mimic other health problems in the horse and signs can range from mild to severe. The sooner EPM is diagnosed and appropriately treated, the better the chance of recovery. 

Prevention

There are several things horse owners can do to reduce the risk of exposure to the parasite:

 

• Keep feed rooms and storage containers closed and securely covered

• Minimize the possibility of wild animals accessing horse feeders

• Clean up any dropped grain immediately to discourage scavengers

• Feed heat-treated cereal grains and extruded feeds since these processes seem to kill the infective sporocysts

• Keep water tanks clean and refill water tanks with clean, fresh water frequently

• Maximize your horse's health and fitness through proper nutrition, regular exercise and routine preventative care (vaccinations, deworming)

• Schedule regular health check-ups with your veterinarian

Treatment

Don’t stall. The sooner you consult with a veterinarian to obtain an accurate diagnosis, the sooner treatment can begin. A delay in treatment allows the disease to progress, potentially causing additional permanent damage to the nervous system.  

 

Marquis® (15% w/w ponazuril) antiprotozoal oral paste is the first FDA-approved treatment for equine protozoal myeloencephalitis (EPM). The active ingredient, ponazuril, crosses the blood-brain barrier and targets the merozoite stages of the protozoa without affecting mammalian cells making it a safe choice for horses.1 In animal safety studies, loose feces, sporadic inappetence, weight loss, and moderate edema in the uterine epithelium were observed.

 

Good nursing care and supportive therapy are recommended to reduce clinical signs, and aid healing of affected nervous tissue. Consult with your veterinarian about supportive treatment options such as anti-inflammatories, antioxidants, and immunomodulators.

Marquis package shot with box and syringe

MARQUIS®
(15% w/w ponazuril)

One of the most common equine central nervous system disorders is equine protozoal myeloencephalitis (EPM).

MARQUIS®
(15% w/w ponazuril)

One of the most common equine central nervous system disorders is equine protozoal myeloencephalitis (EPM).

Marquis package shot with box and syringe

MARQUIS IMPORTANT SAFETY INFORMATION: The safe use of MARQUIS in horses used for breeding purposes, during pregnancy, or in lactating mares has not been evaluated. In animal safety studies, loose feces, sporadic inappetence, lost weight, and moderate edema in the uterine epithelium were observed. For use in animals only. Not for human use. Keep out of reach of children.


 

1. Based on MARQUIS FOI Summaries. Study 141-188 Bayer Corporation.

2. Reed, S. M., Furr, M., Howe, D. K., Johnson, A. L., MacKay, R. J., Morrow, J. K., Pusterla, N., & Witonsky, S. (2016). Equine Protozoal Myeloencephalitis: An Updated Consensus Statement with a Focus on Parasite Biology, Diagnosis, Treatment, and Prevention. Journal of Internal Veterinary Medicine, 30, 491–502.

 

Marquis® is a registered trademark of the Boehringer Ingelheim Animal Health USA Inc. ©2021 Boehringer Ingelheim Animal Health USA Inc., Duluth, GA. All rights reserved. US-EQU-0130-2021