This does not appear to cure horses from shivers but it may reduce the frequency of muscle spasms. Many shivering horses are hesitant to lie down when confined indoors and as a result may lose body condition, and consequently appear older. This behavior, although typical of the disease, is not constant.Occasionally there is involvement of the muscles of the forelimb, neck, or even trunk and face. On attempting to lift a front foot the limb is thrust forwards in full extension, the foot barely touching the ground, or the limb with the carpus flexed is elevated and abducted, the extensor muscles above the elbow quivering while the spasm lasts or until the foot returns to the ground.
In ponies, shivers is considered uncommon to rare. While normal horses acquire these fiber changes through exercise, horses with Shivers lack the “off-switch” the cerebellum normally provides for muscle contraction, causing the muscles to constantly be active. If vitamin E levels are below normal limits then supplementation is recommended. The clinical spectrum of shivers in horses is very variable in the degree or manifestation of signsThe most characteristic signs of Shivers occur when an attempt is made to move the horse backwards. By: Dr. Lydia Gray, SmartPak Medical Director/Staff Veterinarian Updated 2/27/2020 Introduction. Furthermore, the muscles of horses with Shivers show a significant change in fast twitch type 2x muscle fiber type similar to horses in intensive training. How to Manage a Horse with Shivers Dr. Lydia Gray, SmartPak Staff Veterinarian and Medical Director, discusses how to manage a horse diagnosed with shivers, including signs and symptoms, as well as predisposing factors. Adequate levels of vitamin E are important. His symptoms Case Report from Waddell, Arizona, USA (thank you Carol Stinner)“Lily is a 9 year old grey warmblood mare who after being started at age 4 had issues: no forward, grumpy, Case Report from Ft. Myers, Florida, USA (generously contributed by Julie Griffin)“Luna” is a grey 12 year old Oldenburg/Thoroughbred mare. Both genders can be affected, but geldings are three times more likely to be diagnosed with the disorder. Vitamin levels in serum should be checked (blood taken, the blood tube protected from light, kept chilled and spun down as soon as possible). Thhis will not change the current signs of shivers but it may possibly slow progression to ensure the horse is not deficient. Symptoms were relieved the more these horses moved around.At present, there is no cure and few effective treatments for Shivers. Signs are not apparent at the trot.
Usually horses with Shivers will show signs before age 10. Most horses with Shivers begin to show signs before 5 years of age, and the majority of cases (74% of horses surveyed in a recent study) are progressive in severity. However, a study done by researchers at the University of Minnesota showed that the PSSM in Belgian Draft Horses does not have a direct relationship with PSSM and their appearance in the same horse is likely coincidental rather than causal.
Horses with Shivers often move forward normally and can even reach high levels of athletic competition, but have extreme difficulty with less natural gaits such as backing up or lifting a hindlimb. Researchers have noted that the breeds of horses affected by Shivers also have particularly high coincident rates of polysaccharide storage myopathy. Many horses that hold a hind limb flexed and tremble are said to have Shivers.
As noted above, shivers in horses has a long equine history and has, over the centuries, been described as being relatively common or uncommon and rare or very rare. Mildly affected horses show tenseness or trembling of the hind limbs and sudden jerky extensor movements of the tail that cause it to elevate. Usually horses with Shivers will show signs before age 10. It has been suggested that dietary treatment of affected draft horses with a high-fat, low carbohydrate feed may be beneficial if instituted early in the course of the disease.
Reports from past centuries suggest that shivers was prevented by breeding away from the condition. Shivers or shivering are names that have been applied to a chronic neuromuscular syndrome in horses that has been recognized for centuries. Shivers is also characterized by uncoordinated, jerky muscle contraction or myoclonus, an effect linked to cerebellar damage in human studies. Monday–Friday, from 8:00 a.m.–1:00 p.m., the ECCM Service will operate as a “referral only” service. In advanced cases, the affected animal may be unable to move backward more than a few paces, and sometimes this movement cannot be performed at all. When the muscles of the head or neck are involved, they contract spasmodically. Excessive sweating has been noted in some cases.The ultimate causes of Shivers remain unknown. However, the clinical signs of shivers in horses did not resolve when affected Warmblood or Warmblood-cross horses were fed grass hay and their dietary grain was replaced with a high fat supplement.