402 



DISEASES OF THE FEET. 



net and on the pastern; the redness is succeeded by an erup- 

 tion, the crop of pimples or vesicles being generally more 

 numerous above the bulbs of the heels. The eruptive stage 

 does not continue long, the blisters burst or dry up and form 

 a layer of scabs, which finally fall off or dessicate, leaving 

 the parts more or less denuded of wool for some time subse- 

 quently ; indeed it may be stated that the condition of the coro- 

 nary skin is very similar to that which is induced by the action 

 of an ordinary cantharides blister, and the changes occurring on 

 the skin of the coronet may be classified under four heads, 

 namely, redness, vesication, scab, and dessication. 



The inflamed and vesicular condition of the skin is thought by 

 some observers to extend into the sensitive foot, and no doubt this 

 is a correct and proper view to take of the disease, .and accounts 

 for the very severe lameness observable in the earlier stages, 

 the early detachment of the horny digits from their connecting 

 laminae,^ and for the presence of lameness in some instances 

 before the occurrence of perceptible redness of the coronary sub- 

 stance. Immediately on the appearance of vesication, and some- 



FiG. 79 shows the condition of a foot four weeks after 

 the first or febrile stage. 



times even prior to that event, the horny walls separate, more 

 particularly at the posterior part of the feet, sometimes yerj 

 slightly, occasionally a mere line of attempted separation being 

 observable, at other times more completely, from their attach- 



* Vesication round the coronet should not necessarily produce separation of the 

 horn therefrom ; nor does it, unless, as in eczema cpizootlca, where, in even 

 Blight cases, the vesicles will be found to extend underneath the coronarj' band. 



