CAUSES OF UNSOUNDNESS. 127 



disease, whereas others have it but slightly. It 

 consists of a shivering or trembling movement with 

 either the hind or fore hmbs when the animal is made 

 to back. It is generally the hind limbs that are 

 affected, and great difficulty is experienced when 

 the horse is compelled to back. Many a shiverer 

 has been sold as a sound horse because there is 

 often great difficulty in detecting it. In fact, one 

 may have to wait weeks or months before it can 

 be found out. Evidence of this disease may show 

 itself by a slight uplifting and quivering movement 

 of the tail, best observed when the animal is drink- 

 ing, or immediately after it comes in from work. 

 The question may be asked, " Can a horse suddenly 

 develop this disease ? " To this no answer can be 

 given, but if shivering is detected in a horse, recently 

 purchased, with a general warranty, it is usual to 

 presume that it had the complaint at the time of 

 sale. But no expert evidence can be given in sup- 

 port of this view, and the seller's argument that it 

 may have come on since the time of purchase, is 

 as likely to hold good as the plea that it existed 

 at the time of sale. Speaking strictly, shivering is 

 a disease without any pathological facts sufficiently 

 significant to estabhsh' a general rule relative to its 

 causation. Hence, the reason why it is impossible 



