THRUSH. 423 



dependent orifice, ascends, torturing the animal to a dreadful extent, and 

 breaks out at the coronet. These cases are very troublesome. Sinuses 

 are formed, and the evil may end in quittor. A large and free dependent 

 orifice must then be made, and a poultice applied ; to Avhich should succeed 

 a solution of sulphate of zinc, with the a|3plication of the compound tar 

 ointment. 



The cause of corn is a most important subject of enquiry, and which a 

 careful examination of the foot and the shoe will easily discover. The cause 

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

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

 and afterwards with the shoe nailed on the outside, 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 de- 

 scribed) should be used, with a web sufiiciently 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, in order to give them 

 a level surface. 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. There is nothing 

 perhaps in which the improvement in the veterinary art has relieved the 

 horse from so much suffering as shoeing, 



THRUSH. 



This is a discharge of offensive matter from the cleft of the frog. It is 

 inflammation of the lower surface of the sensitive fi'og, 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 httle way into it ; but when it becomes 

 conti-acted or otherwise diseased, it extends in length, and penetrates even 

 to the sensitive lamince within, and through thisunnaturally deepened fissure 

 the thrushy discharge proceeds. A plethoric state of the body may be a 

 predisposing cause of thrush, but the imnaediate and grand cause is 

 moisture. This should never be forgotten, for it will lead a great way 

 towards the proper treatment of the disease. If the feet are habitually 

 covered Avith any moist application — his standing so miuch on his own 

 dung is a fair example — thrush will inevitably appear. It is caiised 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 per- 

 nicious effects of the dung and the urine, moistening, or as it were mace- 

 rating, and at the same time irritating them. The distance of the hinder 

 feet from the centre of the circulation would also, as in the case of grease, 

 more expose them to accumulations 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 frog fi'om the wiring in of the heels will produce pain and 

 inflammation: and the inflammation, by the increased heat and suspended 

 function of the part, wiU dispose to contraction. Horses of all ages, and 

 in almost all situations, are subject to thrush. The unshod colt is 

 fi'equently thus diseased. 



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

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

 disease can only be detected by close examination, or the pecuKar smell of 



