400 INFLAMMATION OF STRUCTURES ENCLOSED BY THE HOOF. 



sensitive wall, or when severe pain has existed uninterruptedly 

 for a long time, operation is advisable and can only be suc- 

 cessfully attempted by a veterinary surgeon. If, however, 

 suppuration is only slight, and pain insignificant, the best 

 treatment is to thin the neighbouring parts, expose the sup- 

 purating spot, and then to dress and plug the cavity with a 

 20 per cent, solution of iodoform in ether. This treatment 

 should be repeated at every shoeing until improvement occurs. 

 The latter, however, depends principally on thorough cutting 

 out and cleansing of the suppurating spot. 



Shoeing. — When the wall is good an ordinary shoe is suffi- 

 cient, but if broken away or diseased a bar shoe, well seated 

 out at the affected part, is preferable. The spot itself should 

 be relieved of all pressure. 



8. Canker of the Frog or Sole 



is a peculiar intractable disease of the corium, which always 

 tends to become aggravated, and which is attended with pro- 

 liferation of the sensitive papillae or laminae, disturbance in 

 the ordinary formation of horn, and the secretion of a thick, 

 offensively smelling lluid. It usually begins unnoticed in one 

 of the lateral furrows of the frog, less frequently in the sole, 

 and is only detected after having made considerable progress. 

 A moist discharging spot, from which the horn has been 

 shed, is then noticed. Its base is pale red, swollen, and spongy, 

 and not infrequently the sensitive frog, sole or wall exhibits 

 warty, cauliflower-like or brushy growths. There is seldom 

 lameness at this stage. The disease makes steady but slow 

 progress, and a long period may elapse before it extends from 

 the frog to the wall. At a later period the hoof, if not already 

 very oblique, increases in width towards the heels. 



The causes are not yet sufficiently known. Slight inflamma- 

 tion due to bruising, especially when the corium is exposed, is 

 said to be sufficient to cause an attack. Although canker is 

 quite distinct from thrush, the latter disease seems to favour 

 the production of canker. 



The prognosis is unfavourable and should always be guarded. 

 The principal indications are afforded by the condition of the 



