8o CAUSES OF UNSOUNDNESS. 



animal is blind. It may be either temporary 

 or permanent, and appears to be due to paralysis 

 of the optic nerve, or retina. In some cases, ex- 

 cessive haemorrhage is a cause. But any inter- 

 ference with the normal functions of the optic nerve, 

 such as pressure from a tumour, morbid growth, 

 etc., is also liable to cause it. A horse might 

 be sold as sound to-day, but within a few hours 

 afterwards, the paralytic condition of the eye be 

 observed. In the writer's opinion, no redress for 

 such could be obtained, because veterinarians are 

 fully aware that the disease may be produced by a 

 fall upon the head, etc. Amaurosis is indicated by 

 the widely-dilated pupil, and the non-responsive 

 nature of the pupil when the horse is brought into 

 the hght. 



Blindness. —The term blindness is somewhat 

 ambiguous and capable of wide interpretation ; for 

 instance, a horse may be partially or completely 

 bhnd, or the blindness may affect one or both eyes, 

 and be either temporary or permanent, in accordance 

 with the nature of the causes of the defective vision. 

 The duration of bUndness likewise varies, but, as 

 a rule, most forms of it are permanent. A re- 

 markable feature in connection with a blind horse 

 is the condition of its coat. In summer it develops 



