126 CAUSES OF UNSOUNDNESS. 



when it is compelled to stand over in the stall. 

 It is an incurable disease, and universally recog- 

 nized as constituting unsoundness, though it may 

 not interfere with the utility of the animal. It 

 does, however, ultimately tell upon the functional 

 activity of the Hmb, and an animal affected with 

 this complaint is more Hable to develop such 

 diseases as would be produced by concussion — e.g., 

 side-bone, ring-bone, bone-spavin, etc. Some 

 horses are only slightly affected with string-halt, 

 whereas others have the disease in a very severe 

 form. In rare instances it has been observed in 

 the fore limbs. It may be developed suddenly 

 after external injury, or without any visible cause. 

 There is what is sometimes termed " symptomatic 

 string-halt" — that is, a sudden jerking of the limb 

 accompanying a sprain, etc. The causes of string- 

 halt are variable, but such diseases as bone-spavin 

 and ring-bone, as also disease of the pelvic bone, 

 are recognized as having to do with the production 

 of string-halt. It must be considered, however, as 

 one due to impaired functional activity of the 

 muscles and nerves of the hind limbs. 



Shivering, or Chorea. 



Some horses arc very badly affected with this 



