8 April, 1908.] Diseases of Farm Animals. 195 



whereby the scab and discharges are pressed into the sore instead of 

 being allowed to peel off. The mass of dead matter acting as a foreign 

 body constitutes a persistent irritant and when pressed upon causes the 

 animal great pain, as is evidenced by marked flinching and fear when the 

 spot is touched. The dead mass corresponds in great measure to the core 

 of a corn on the human toe ; its existence has been brought about by the 

 same cause, viz. : — pressure, and the pain which is experienced is main- 

 tained in the same way, viz. : — by the squeezing of the living tissues and 

 nerves underneath the core between the external pressure and the under- 

 lying bone. 



Treatment essentially consists in the removal of the core. In some 

 cases this may be done by grasping it with strong forceps or pincers and 

 forcibly tearing it out. It is, however, often so firmly attached that its 

 removal can only be effected with the knife. Such an operation can be 

 best performed if the animal is cast and chloroformed as the patient is 

 usually very fidgety or vicious when the parts are being interfered with. 

 The margin of the sore should be scarified with the knife at the same 

 time, and the resulting wound dressed with antiseptics in the ordinary 

 way (page 54, Vol. V.). 



Fistulous Withers. 



Fistulous withers are so common in Australia, and so familiar to every 

 horseman, that the term "fistula" is by common acceptation and use 

 applied, almost solely, to a condition of the withers of horses, varying, 

 in succeeding and more grave stages, from a mere pinch or bruise to an 

 utterly incurable mass of callo'used and suppurating tissue the size, per- 

 haps, of a camel's hump, with channels running through it in all direc- 

 tions, and opening in manv places on both sides of the shoulders, back,^ 

 and neck, and including extensive disease of the bones of the spine, andr 

 perhaps, of thi shoulder-blade. 



Without a kowledge of the anatomy of the neck and withers it is 

 difficult to understand why an injury which, if it occurred at almost any 

 other part of the body, would soon be cured, when sustained at this part 

 should result in such a severe wav. Even the slight bruise caused by a 

 pinch of the collar or saddle, or broken saddle-tree, may, if not properly 

 treated, result in an incurable fistula. If, after a bruise or pinch of the 

 withers, cooliaig lotions are applied, and the hor'se rested for a day or two, 

 the mild inflammation soon subsides, and no ill results follow. But if the 

 injury is severe in the first instance, or if a slight cause is allowed to 

 continue to act so as to favour the formation of matter (pus), then the 

 anatomical peculiarities of the part render a fistula inevitable. The 

 muscles of the neck and withers are for the most part broad and flat, 

 and are placed flatly one outside the other and side by side, running from 

 different parts of the neck over and under the shoulder-blade on to the 

 back. Now, when matter forms it has a tendency to gravitate, and always 

 runs in the direction in which there is least resistance. Hence, if the bruise 

 of the withers is at all deer-seated and sufficiently severe to result in the 

 formation of matter, then this matter verv soon burrows its wav down in 

 the interstices between the muscles, and is there imprisoned. So lodged, 

 it never "points" through the muscles towards the surface, but remains 

 and acts as an irritant, and sets up a productive inflammation, resulting 

 in the formation of a callous swelling. By ard by there is an effort of 

 nature to get rid of the imprisoned matter by the formation in the calloused 

 flesh of tubes or channels (sinuses), which run in all directions through it. 



