THRUSH. 183 



inflammation the lower surface of the sensible frog secretes 

 pus instead of the horny substance, which is its proper 

 function. When the frog is in a healthy condition, the cleft 

 sinks but a small way into it. Contraction, however, or any 

 other disease, affects the cleft so that it extends in length 

 and often penetrates deep into the sensible horn within, and 

 it is through this diseased and deepened fissure that the 

 matter from the thrush discharges itself. Any complaint 

 which affects the healthy condition and action of the frog, 

 is almost sure to induce thrush. Differing from most dis- 

 eases of the foot, thrush is generally more severe in the 

 hind than in the fore feet. This can only be accounted for 

 by bad stable management, and that the hind feet are sub- 

 jected to being so much exposed to the baneful conse- 

 quences of immersion in the dung and urine, producing 

 irritation, and generating disease. Besides, the hind feet are 

 further removed from the centre of circulation than the 

 fore, which consequently subjects them to the accumulation 

 of matter and grease, as well as other affections to which 

 they are liable. Contraction is generally the cause of 

 thrushes in the fore feet. Wiring-in of the heels will 

 produce pressure on the frog, and cause pain and inflam- 

 mation. 



A horse may have thrush without being lame, and it 

 often happens that no alteration whatever can be seen on 

 the foot thus diseased, and it may require a close inspection 

 to detect that it is affected. But it will always be mani- 

 fested by the disagreeable and peculiar smell which inva- 

 riably accompanies the complaint. In some cases no 

 tenderness of the frog attends thrush, and therefore the 

 horse is not reckoned legally unsound by many persons. 

 This we, however, consider strange, as it is a complaint 

 which may, and indeed is likely to assume a worse aspect; 



