108 The Management and Treatment of the Horse, 



its proper function. When a frog is in a healthy con- 

 dition the cleft sinks but a small way into the foot ; 

 contraction, however, or any other disease, often 

 affects the cleft so that it extends in length and often 

 penetrates deep into the sensitive frog, and it is 

 through this deep and diseased fissure that the matter 

 from the thrush discharges itself. Any complaint 

 which affects the healthy condition of the foot will 

 induce thrush, which, differing from most diseases of 

 the foot, is mostly the worst in the hind feet, especially 

 in horses kept in the stable. This can be accounted 

 for by uncleanliness and bad stable management, and 

 that the hind feet aie subject to the baneful effects of 

 being immersed in the dung and urine, producing 

 irritation and generating disease. Besides the hind 

 feet are farther removed from the centre of circulation 

 than the fore feet, which consequently subjects them 

 to an accumulation of matter and grease, as well as 

 other affections to which they are liable. Contraction 

 is generally the cause of thrush in the fore feet, and 

 contraction is caused chiefly by bad shoeing and neg- 

 lect of the foot of the unshod colt, therefore I contend 

 that I am within bounds when I assert that thrush is 

 caused by man's neglect. A horse may have thrush 

 without being lame, as it often happens that no 

 alteration whatever is to be seen on the foot thus 

 diseased, and it may require a close inspection to 

 detect that it is diseased, but it will always be 

 manifested by the disagreeable smell that invariably 

 accompanies this complaint. In some cases no ten- 

 derness of the frosj attends thrush, and the horse 



