ETIOLOGY AND OCCURRENCE 35 



the underlying sensitive parts of the feet and lameness is the in- 

 evita])le outcome. 



The function of the feet — bearing the weight of the animal at 

 all times when the subject is not recumbent, and in addition to 

 this, the increased strain put upon them at heavy draft work, 

 together ^^ ith the concussion and l)uffeting occasioned by locomo- 

 tion, make the feet susceptible to frequent affections of various 

 kinds. 



Being almost completely encased by a somewhat inexpansible 

 and insensitive wall and sole, renders the foot subject to path- 

 ologic changes peculiar to itself. The very nature of the struc- 

 ture of the foot together with the function of the sensitive lamina 

 is sufficient cause for an affection unlike that seen involving other 

 tissues — laminitis. 



An exhaustive consideration of foot affections is a study in 

 itself and one that comes within the realm of pathologic shoeing; 

 nevertheless, a practical knowledge of diseases of the foot is 

 indispensable in the diagnosis of lameness wherein the foot may 

 be at fault. 



The peculiar nature of foot affections renders them difficult 

 of classification on any sort of basis that is helpful in the con- 

 sideration of this subject. Injuries are the most constant cause 

 of foot lameness, yet one must admit that there results compli- 

 cations because of infection in most instances ; and that in some 

 cases the injury is slight — just enough to permit the introduction 

 of vulnerant organisms into the tissues. Therefore, one might 

 well classify affections of the feet as infectious and non- 

 infectious. There can be grouped in the class of infectious af- 

 fections such conditions as nail pricks, calk wounds and canker. 

 In the class of non-infectious affections one may consider condi- 

 tions such as laminitis. strain and fractures. 



