Your Guide to Equine Health Care

Where We Stand With Shivers

Learn the latest about this puzzling neuromuscular disease.

No account yet? Register


Shivers is a chronic neuromuscular disease that causes gait abnormalities in affected horses, evident as they are backing up. Other signs include trembling of the tail when the horse holds it erect, trembling of the thigh muscles, and a flexed and trembling hind limb.

Most horses with shivers begin to show signs before 5 years of age, and most cases (74% of horses in a recent study) become progressively more severe. While shivers can affect horses of any sex, geldings are three times more likely to be diagnosed with the disorder than mares. Horses taller than 16.3 hands are also more susceptible than shorter horses. The syndrome affects several breeds, including draft horses and Warmbloods, and occasionally lighter breeds, including harness horses, Quarter Horses, and Thoroughbreds.

Diagnosing shivers is straightforward when signs are clear; however, milder cases are more difficult to pinpoint. If your horse exhibits muscle quivering, difficulty backing up, discomfort while being shod behind, or other signs of shivers, have him evaluated by your veterinarian to rule out other painful conditions and possible causes of lameness, such as stringhalt and upward fixation of the patella.

As disease progresses, gradual and progressive hind limb muscle atrophy (wasting) can occur. In the aforementioned study, 11 of 19 horses with shivers (58%) exhibited hindquarter weakness. Severely affected animals might not lie down. These sleep-deprived horses often develop wounds on the fronts of their fetlocks from dozing while standing. Advanced cases may adopt an abnormal base-wide stance behind. Veterinarians have noted excessive sweating in some

Create a free account with to view this content. is home to thousands of free articles about horse health care. In order to access some of our exclusive free content, you must be signed into

Start your free account today!

Already have an account?
and continue reading.


No account yet? Register

Written by:

Stephanie Valberg, DVM, PhD, Dipl. ACVIM, ACVSMR, is the Mary Anne McPhail Dressage Chair in Equine Sports Medicine and a Professor of Large Animal Clinical Sciences at Michigan State University. She is a leading researcher on the subject of tying-up and the genetic basis for equine neuromuscular disorders.

Related Articles

Stay on top of the most recent Horse Health news with

FREE weekly newsletters from

Sponsored Content

Weekly Poll

sponsored by:

This poll is no longer accepting votes

Which hoof problem do you encounter most often in your horses?
342 votes · 342 answers

Readers’ Most Popular

Sign In

Don’t have an account? Register for a FREE account here.

Need to update your account?

You need to be logged in to fill out this form

Create a free account with!