382 DISEASES OF THE FEET. 



A corn constitutes an unsoundness, although it may not at the 

 time cause lameness. 



Treatment. — If inflammation be present, treat accordingly; 

 remove shoes ; poultice, &c. Give exit to pus if the corns have 

 festered ; and if there be superficial necrosis of the pedal bone, 

 the sequestrum must be removed. The radical cure, however, 

 is to be effected by proper shoeing, and the method already laid 

 down is certain, speedy, and recommends itself to all impartial 

 men. Horses that are high steppers, with heel action, are most 

 susceptible to corns, especially if weak in the heels ; but corns 

 are seen in the best of feet, and they will continue to be seen 

 while horses are shod with the seated shoe. One other cause 

 of corns is the maceration of the feet by vile combinations called 

 " stoppings," which cannot be too strongly condemned. 



THRUSH. 



A discharge of a foetid material from the frog, arising from a 

 diseased condition of the secretory surface of the fibro-fatty frog. 

 The cleft is the part commonly first affected, and when neglected 

 the disease spreads over the whole organ ; the horn becoming 

 detached from the bulbs of the heels to the toe of the frog. 

 The causes are extrinsic and intrinsic. The extrinsic causes are 

 filth, the irritating materials generated in the decomposition of 

 the urine and faeces, and contained in stoppings for the feet, such 

 as cow-dung, and maceration of the frog, as when the animal is 

 turned out to a wet pasture : these causes operate by destroying 

 the integrity of the horny frog, and irritating its sensitive 

 counterpart. Thrushes from extrinsic causes are more com- 

 monly found in the hind than in the fore feet, because the latter 

 are not in the dirt while the animal is in the stable. The intrinsic 

 causes operate chiefly on the fore feet, — although thrushes may 

 be seen in the fore feet if the animal be at grass, in a wet straw- 

 yard, or in a dirty loose box. In the winter time the frog 

 denuded of its horn becomes occasionally frost-bitten, leading 

 to deep sloughing, which may even extend to the navicular bursa, 

 and causing great lameness. 



Thrushes are easily cured, when originating from external 

 causes, by cleanliness, and calomel locally applied ; and if it be 

 impossible to prevent the animal from standing in his excreta, 



