SHIVERING. 1027 



XL— SHIVERING. 



" Shivering " is the name applied to a peculiar neuro -muscular 

 disease, characterised by involuntary spasmodic muscular con- 

 tractions with consequent irregular movements, generally affecting 

 one or both hind-limbs and the tail ; sometimes only a fore-limb, 

 or occasionally the limbs, lips, cheeks, eyelids and neck. 



Shivering is often regarded as hereditary, but the cause has not- 

 been ascertained. Frequently its occurrence is preceded more or less 

 remotely by an attack of strangles, influenza, or pneumonia ; and 

 this fact has led many observers to suggest that shivering is con- 

 nected with neuropathic lesions produced by infection, or toxins 

 derived from antecedent disease. Shivering is sometimes attributed 

 to accidental injuries, falls, fright, &c. 



It occurs at all ages, and while principally affecting draught - 

 horses, it is frequently seen in light harness horses, hunters and 

 hacks, and occasionally in thoroughbreds. It is very rare in 

 ponies. 



Symptoms and diagnosis. Shivering varies very much in degree 

 or manifestation. The symptoms may be constant and easily seen, 

 or intermittent, occasional or latent and very difficult to discover. 

 Many shivering horses only exhibit the symptoms when being shod, 

 or when moving over in the stall ; others while standing in harness 

 constantly attract attention by frequently raising and abducting the 

 shivering hind-limb. In well-marked bilateral posterior shivering, 

 the horse in advancing may give no sign of the disease, or the symptoms 

 may be restricted to the first two or three steps ; but on lifting a 

 hind-foot, or in backing the horse, the limb is suddenly raised, semi- 

 flexed and abducted, shaking or shivering in suspension, the super- 

 ficial muscles of the thigh and quarter quivering, while the tail is 

 elevated and tremulous. In a few moments the spasms cease, the 

 limb is slowly extended and the foot brought to the ground. In 

 severe cases the horse exhibits symptoms on every occasion he is set 

 back, turned round, or moved from side to side. He may be unable 

 to move backwards, or to lie down, and if he should fall, unable to 

 rise without assistance. 



Diagnosis of cases in which the symptoms are slight or inter- 

 mittent usually requires patient observation of the animal in the 

 stable or the forge. Hammering the foot or shoe, allowing the horse 

 to drink from a pail placed on the ground, forcibly backing the horse 

 up hill over rough setts, or slippery pavement, or puncturing the 

 pastern with a pin may reveal the symptoms. Repeated testing of 



