CANKER. 169 



is not on the same level on both sides. I have seen, in two or three 

 instances, the coronet over an inch higher up the pastern at one 

 heel than at the other. Although I have not had an opportunity 

 of examining by dissection any such case after death, I feel assured 

 from the appearance of these feet, that one wing of the pedal bone 

 must have been twisted either upwards and inwards, or downwards 

 and inwards, as the case may have been. In the very few instances 

 that have come under my observation, only one side appeared to 

 be affected. Such a condition will, almost to a certainty, give rise 

 to very obstinate thrush, and ^vill render it difficult to afford the 

 foot a level and properly adjusted " bearing," whether the animal 

 be worked barefoot or in shoes. Although the probability of effect- 

 ing a radical cure in an aggravated case of this kind would be 

 remote, we should endeavour to palliate the condition, as much as 

 possible, by keeping the heels very low, so as to get as much frog 

 pressure as we can (see treatment of " Thrush," page 166) ; attend- 

 ing to the thrush, if present; and letting the animal go barefoot, 

 or using " tips," If these simple means be of no avail, we may try 

 the effective one of cutting, through the wall of the hoof, a groove 

 from the coronet to the ground surface of the foot, so as to isolate 

 the abnormally turned in portion of the wall which is close to the 

 heels, from the remainder of the hoof. The groove should be made 

 as deep as possible without drawing blood, in a manner similar 

 to that described for sandcrack (pp. 178 and 180), and should be 

 kept filled with beeswax while the foot is growing down. 



The appearance of slight contraction, due to the natural form of 

 the foot being narrow, is compatible with health. So long as the 

 contraction does not co-exist wdth disease, other than thrush, or 

 with any infirmity which prevents the horse from placing his foot 

 " fair " on the ground, or with malformation ; the foot can be re- 

 stored to a healthy and natural state, in a short time, by the means 

 already described. 



LEGAL ASPECT.— If contraction of the hoof is liable to pro- 

 duce lameness, it is an unsoundness. See Greenway v. Marshall, 

 9th Dec, 1845, which case was tried before Chief Baron Pollock. 



Canker. 



DEFINITION. — Canker is a chronic and apparently an infective 

 inflammation of the membrane which secretes the sole and frog, 

 and which is a continuation of the skin of the pastern. This 

 membrane covers the pedal bone. Canker seems to bear the same 

 relation to thrush, as gi'ease does to cracked heels. Spontaneous 

 recovery from it does not appear to be possible. 



