312 DISEASES OF THE HORSE'S FOOT 



The serous matter exuding from the diseased keratogenous 

 membrane appears, in fact, to be highly infective. Once 

 its flow is commenced, it slowly, but surely, invades the 

 sensitive structures near it, appearing, as Blaine has put it, 

 to ' inoculate ' them. What is really the case, of course, is 

 not that the discharge itself is infective, but that it is con- 

 taminated with infective material. 



The fungoid-looking growths to which we have before 

 referred, are in reality, nothing more than the villi of the 

 sensitive frog and sole greatly hypertrophied and irregular 



Fig. 135. — Lower Aspect of Cankered Foot, showing 

 Destruction of Wall. 



in shape. At times the hypertrophy is as a huge and 

 compact enlargement occupying the position of the frog. 

 Sometimes, however, it occurs as numerous elongated and 

 twisted fibrous bundles, separated from each other by deep 

 clefts, and the clefts filled with the offensive cankerous 

 discharge (see Fig. 134). 



At a very advanced stage canker leads to destruction 

 of much of the horny sole and frog; or even parts of the 

 wall may become separated from the tissues beneath, and 

 break away from the foot (see Fig. 135). At other times 



