1052 DISEASES OF THE FOOT. 



complication, necrosis of the laminae, and even of the os pedis, being 

 more frequently seen. As already remarked, the result depends 

 more on the kind and degree of infection than on the extent of injury. 

 Direct injuries of the bone lead, as a rule, to necrosis, which is apt to 

 invade the neighbouring sensitive structures. 



The diagnosis is based partly on the fact that the horse goes lame 

 soon after shoeing and partly on examination of the hoof. For this 

 purpose the shoe is removed, and the ground surface of the hoof, and 

 especially of the white line, well cut out, so that the position of each 

 nail-hole can easily be detected. If it is necessary to expose a nail 

 tract, it should first be followed through the horn of the sole and 

 white line, the wall being spared, so as to preserve a sufficient bearing 

 surface for the next shoeing. 



Causes. Want of care and skill on the part of the farrier is the 

 usual cause of stabs or pricks, though they may be due to bad feet 

 and to the animal's restlessness, without any fault on the part of 

 the farrier. Carelessness in shoeing is shown by the nail holes being 

 misdirected, and by their occurring at points where there was not 

 sufficient horn to warrant the driving of a nail. The usual causes 

 of stabbing are coarsely -punched nail holes and insufficient horn ; 

 stubs left in the feet rarely occasion pricks by causing the nail to 

 deviate from its normal direction. 



The first step in treatment is to remove the nail and shoe. 

 Provided suppuration has not set in, cold applications, in the form of 

 antiseptic foot-baths or poultices, may be tried. The part must be 

 cleansed, and infection prevented by applying a suitable dressing. 

 Once suppuration occurs, treatment follows the above-described 

 principles. 



II.— PICKED-UP NAILS. PURULENT CELLULITIS OF THE PLANTAR 

 CUSHION. RESECTION OF THE FLEXOR PEDIS PERFORANS. 



The above title will, for convenience, be regarded as including all 

 injuries caused by the animal treading on foreign bodies which thus 

 penetrate the soft structures of the foot. Such bodies include nails 

 and wire, as well as pieces of iron or glass. As the horny sole usually 

 offers sufficient protection, such foreign bodies almost invariably 

 enter through the frog, and may injure the plantar cushion, or perforans 

 tendon, navicular sheath, os pedis, os naviculare, or pedal joint. 

 On account of their different behaviour when injured, we distinguish — 

 (1) a horny frog, (2) a sensitive layer, and (3) a fibro-fatty frog. The 

 two latter are usually included under the term " plantar cushion." 



