DISEASES OP THE FOOT. 505 



frog. Nature has made the frog as a cushion or elastic pad, on which to 

 receive concussion and to lessen it in other parts of the frame. If the 

 frog be subjected to a fair amount of wear and pressure before the dis- 

 ease has run too great a length, it will probably again become sound and 

 strong. 



^ 



1018. Neglected Thrush. 



If Thrush is long neglected, the neighbouring parts become affected, 

 and in bad cases the whole of the sensitive sole is involved. The sole is 

 then said to be " under-run ; " or in other words the unhealthy secretions, 

 being greatly increased and unable to find sufficient exit through the 

 insensitive frog, burrow between the sensitive and insensitive sole. The 

 disease, if still further neglected, may run into canker. The treatment 

 of serious cases of neglected thrush is nearly similar to that required in 

 canker, which will be described in the succeeding paragraph. 



1019. Canker. 



Canker is a morbid secretion of the sensitive frog and sole, involving 

 of course the corresponding insensitive parts. This formidable disease 

 usually has its origin in neglected thrust, but it may be due to constitu- 

 tional causes. It is most common in heavy cart horses. 



The discharge, which issues from the frog, is more or less copious, 

 foetid, and colourless. The frog itself becomes large, spongy, and 

 covered with pallid stringy prominences of a fungoid nature, intermixed 

 with offensively-smelling, semi-dried, cheesy masses of matter composed 

 of imperfect horn-cells. ^The smell is disgusting. 



1020. Treatment. 



The treatment of Canker consists 1st, in the complete exposure of the 

 diseased surface ; 2nd, in the application of pressure ; 3rd, in thorough 

 dryness. 



The whole, not merely the diseased portion, but the whole of the 

 insensitive sole must be removed. When this has been thoroughly and 

 effectively done, the whole of the exposed surface must be dressed with 

 nitric acid. The sole must then be firmly packed with dry tow secured 

 with a bandage,' and the foot enclosed in a leatnern boot. This will give 

 the necessary pressure. To prevent excessive bleeding from the removal 

 of the sole a tourniquet should be applied to the fetlock. The foot, 

 bedding, and sole must be kept scrupulously dry. 



After two days the dressing should be removed. In favorable cases 

 the whole of the exposed surface of the foot will present a healthy appear- 

 ance, and will gradually become covered with good horn, and no further 

 treatment will be required beyond cleanliness, dryness, mild astringents, 

 and moderately firm pressure and bandages. For at least a week after 

 the operation the horse should stand without shoes. But as soon as the 

 feet are able to bear shoes, they should be applied, as it is much easier 

 to dress the feet with shoes on. 



