FOLLOWING INDIVIDUAL HOOF DISEASES. 147 



cartilage is ossified, and the diagnosis then often becomes 

 uncertain. If pressure upon the corresponding portions of 

 the wall fails to produce pain, the diagnosis of side bones 

 can only be pronounced when all other lesions, which might 

 excite similar lameness, are excluded. 



Fig. 27. 

 Ossification of the lateral cartilages. 



8.— Thrush. 



Rarely gives rise to lameness, unless the horny frog has 

 been destroyed to such an extent as to no longer be a protec- 

 tion to the sensitive frog, which may even become visible. 

 Such animals go lamer on soft than on hard and level 

 ground. Ordinarily a thrushy frog looks ragged, and a 

 greasy, grayish matter, having a disagreeable odor, oozes 

 from the middle lacuna, where the disease starts, to possibly 

 undermine the entire frog. Sometimes superficial inflam- 

 mation of the podophyllous membrane follows the entrance 

 of septic material into the spaces formed in the disintegrat- 

 ing frog, producing what is generally known as abscess of 



