THE HORSE, SKIN DISEASES, ETC. 265 



It is sometimes caused by injuries to the frog of tlie foot, as bruising, 

 snagging, and improper shoeing. 



It may arise also from a gross habit of body, producing inlianmiation 

 of tiie sensitive frog, when a spongy substance is deposited instead of 

 sound horn ; and this breaks away and leaves the frog ragged and tender. 



Again, it may come from too frequently stopping soft frogs with cow 

 dung, as is the practice of some grooms, thus encouraging rather than 

 curing decomposition. 



Lastly, it may be secondary, having resulted from other diseases, 

 superinduced by want of cleanliness and care. 



How to Know It. — In some cases, the only means of detecting the 

 existence of thrush is a peculiar smell, or by very careful examination, 

 as the hoof may show no change, and the frog may not be tender. In 

 this case the cleft of the frog will generally be found lengthened and 

 deepened, the opening extending to the sensitive horn within, and this, 

 Avhen thus closely observed, shows discharge of matter. 



The progress of the disease is often slow, though showing meanwhile 

 no disposition to heal ; till after awhile the frog begins to contract, 

 becomes tender, grows rough and brittle, and emits a more offensive 

 discharge. The horny part disappears, and a hardened substance takes 

 its place ; this easily scales off and leaves the sensitive frog uncovered. 



In its advanced state, it is very easily detected, as it "is characterized 

 by a continuous discharge of offensive matter from the cleft of the frog. 

 If not reasonably attended to, proud flesh sprouts up ; and as this spreads 

 the whole foot becomes involved in canker. 



What to do. — In the first place, if the causes which have produced the 

 disease are still in operation, remove these. In any case, when the horse 

 is to be stabled, use dry litter, and see that the stall is kept clear of 

 moist excrement, and that it is well ventilated. 



If the disease is secondary, the treatment must of course b^ directed 

 to removing the affection from which it has sprung. 



In its simple stages, it may be easily cured in the following manner: 



Clean well with soap suds, and allow to dry. Then, wet a piece of 

 cloth or string of tow with the liniment No. 2, and press it into the cleft 

 of the frog and the corresponding part of the heel. Remove the tow^ 

 next morning. Continue this treatment, (putting in the saturated tow at 

 crening), for four days; then omit a day; and so on until a cure is 

 effected. 



Or, sprinkle a small quantity of blue vitriol in the cleft of the frog, 

 and then fill up the cavities with cotton, which so press in as to keep out 

 all dirt. Repeat until the foot is cured. 



