Veterinary advice should be sought before applying any treatment or vaccine.


Shivering, Shiverer, Shivers Syndrome

Shivers is a chronic, often gradually progressive movement disorder of horses. It usually begins before horses reach 7 years of age and occurs most commonly in tall male horses. Shivers is often first noticed when backing up the horse or by picking up a hindlimb.
Image of a typical horse with shivers
Typically, horses with shivers intermittently hold their hindlimb in a flexed position, away from the body for a short duration of several seconds to minutes, while they experience spasmodic muscle tremors in their buttocks muscles and tail. After which, horses will slowly lower the leg back to a normal position.

Horses with shivers are often difficult for farriers to shoe their hindlimbs. Horses with mild cases will often be reluctant to hold their leg up for very long and will often immediately slam their leg back down to the ground. As the disease progresses, the horse may eventually refuse to pick up their feet at all and show exaggerated limb flexion when walking forward. 60 to 74% of horses with shivers show progression of the disease.


Hypertonic flexion or extension of the hindlimbs brought on by walking backwards and manual lifting of the limb
Muscle twitching or tremors
Problems with the farrier trimming hind hooves
Elevated tail head when backing
Reluctance to lay down
Muscle atrophy
Choppy gait
Reduced strength
Exercise intolerance


  • History
  • Clinical signs
  • Physical exam
  • Laboratory tests



Diet changesHigh-fat, low-starch, and low-sugar diet
Increasing physical activityMore frequently exercised or increased turnout
Chiropractic manipulation
Flunixin meglumine
Muscle relaxers
Herbal supplements



Depends on the severity but if severe is guarded to poor.

Scientific Research

General Overviews

Risk Factors

  • Tall, male horses, over 17.1 hands in height
  • Horses that recently received major surgery or were hospitalized for an illness.
  • Horses that were recently put on extended stall rest for an injury
  • Horses that recently had long distance road or airplane travel.

Commonly Affected Breeds

Belgian Warmblood iconDutch Warmblood iconSwedish Warmblood icon