174 DISEASES OF THE FEET. 



having dried tlie diseased surface and thinned the horn around, the 

 bare patch was swabbed with ether, which cleanses the part and 

 also produces a local anaesthesia. The diseased area was then 

 completely covered by the powder, which was well dusted into the 

 lacunae of the diseased frog, and kept applied to the parts by 

 iodised cotton wool, and bandaged in the ordinary way. The 

 dressing was changed daily, and any diseased horn removed ; but 

 after the dressing had been used for ten days, the parts were quite 

 dry, and covered by a thin pellicle of healthy horn. When the 

 powder is applied to the affected parts, a slight crackling is heard, 

 due to the disengagement of the acetylene, which is at once recog- 

 nised by its odour." The same treatment has given excellent 

 results with wounds and grease. 



Above all things, utilise the healthy influence of pressure on the 

 foot, and if possible dispense with shoes, even if slings have to be 

 employed. The floor of the stall or box should be kept scrupu- 

 lously dry and clean, and the animal, if practicable, should be well 

 exercised on dry and soft ground, so as to put pressure on his soles 

 and frogs. With' the same object, the heels and walls of the feet 

 should be kept low. 



Under ordinary methods, cases of canker require several weeks, 

 if not months, of careful treatment. 



LEGAL VIEW. — Canker is a grave unsoundness. 



Sandcrack, 



This is a vertical crack in the wall of the hoof, occurring, in 

 the first instance, close to the coronet. 



CAUSES. — In the healthy foot, the fibres of the wall are firmly 

 held together by adhesive material, which is secreted by the 

 coronet, or, according to some authorities, by the sensitive laminoe, 

 which cover the external surface of the pedal bone. If the secret- 

 ing membrane be subjected to influences which will impair its 

 healthy working, the material secreted under such conditions will 

 to a certain extent be deprived;' of its binding character, and the 

 horn it supplies will consequently be wanting in strength. In some 

 cases — -generally those of hereditary predisposition — the horn is 

 naturally so weak that it would appear liable to split on being 

 subjected to any violent strain. The horn of the feet of almost all 

 horses reared on wet, marshy land is more porous and ready to 

 split than is that of those brought up on dry soil. The pernicious 

 system of using seated shoes and of paring the frog, induces sand- 



