THRUSH. 307 



Next is to be considered the cause of the corn, which a careful exami- 

 nation of the foot and the shoe will easily discover. The cause being 

 ascertained, the effect may, to a great extent, be afterwards removed. Turn- 

 ino" out to grass, after the horn is a little grown, first with a bar-shoe, and 

 afterwards with the shoe fettered on one side, or with tips, will often be 

 serviceable. A horse that has once had corns to any considerable extent 

 should, at every shoeing, have the seat of corn well pared out, and the 

 butyr of antimony applied. The seated shoe (hereafter to be described) 

 should be used, with a web sufficiently thick to cover the place of corn, 

 and extending as far back as it can be made to do without injury to the 

 frog. 



Low weak heels should be rarely touched with the knife, or anything 

 more be done to them than lightly to rasp them, to give them a level sur- 

 face. The inner heel should be particularly spared. Corns are seldom 

 found in the hind feet, because the heels are stronger and the feet are not 

 exposed to so much concussion ; and when they are found there they are 

 rarely or never productive of lameness. 



THRUSH 



Is a discharge of offensive matter from the cleft of the frog. It is inflam- 

 mation of the lower surface of the sensible frog, and during which pus is 

 secreted together with, or instead of horn. When the frog is in its sound 

 state the cleft sinks but a little way into it; but when it becomes contracted 

 or otherwise diseased, the cleft extends in length, and penetrates even to 

 the sensible horn within, and through this unnaturally deepened fissure the 

 thrushy discharge proceeds. It is caused by anything that interferes with 

 the healthy structure and action of the frog. We find it in the hinder 

 feet oftener and worse than in the fore, because in our stable management 

 the hinder feet are too much exposed to the pernicious effect of the dung 

 and the urine, moistening, or as it were macerating, and at the same time 

 irritating them. The distance of the hinder feet from the centre of the 

 circulation would, as in the case of grease, more expose them to accumu- 

 lations of fluid and discharges of this kind. In the fore feet thrushes are 

 usually connected with contraction. We have stated that they are both the 

 cause and the effect of contraction. The pressure on the ti-og from the 

 wiring in of the heels will produce pain and inflammation, and the inflam- 

 mation, by the increased heat and suspended function of the part, will 

 dispose to contraction. Horses of all ages, and in almost all situations, 

 are subject to thrush. The unshod colt is frequently thus diseased. 



Thrushes are not always accompanied by lameness. In a great many 

 eases the appearance of the foot is scarcely, or not at all altered, and the 

 disease can only be detected by close examination, or the peculiar smell ot 

 the discharge. The frog may not appear to be rendered in the slightest 

 degree tender by it, and therefore the horse may not be considered by 

 many as unsound. Every disease, however, should be considered as legal 

 unsoundness, and especially a disease which, although not attended with 

 present detriment, must not be neglected, for it would eventually injui;e and 

 lame the horse. All other things being right, a horse should not be rejected 

 because he has a slight thrush, for if the shape of the hoof be not altered, 

 experience tells us that the thrush is easily removed ; yet if the thrush 

 be not soon removed, it will alter the shape of the foot and the action of 

 the horse, and become manifest unsoundness. The j^ogress of a neglected 

 thrush, although sometimes slow, is sure. The frog begins to contract in 

 size, it becomes rough, ragged, brittle, tender. The discharge is more 



X 2 



