214 BACTERIA PRODUCING DIPHTHERITIC INFLAMMATIONS 



opening there exudes a thin, purulent fluid. The lameness increases 

 and the region of the foot above the hoof becomes swollen and warm to 

 the touch. The exudates from the erosions contain pus cells, bits 

 of destroyed tissues of the foot, and bacteria. It possesses an odor 

 pungent and disagreeable, but at the same time very characteristic 

 This odor is so pathognomonic of the disease that it would reveal the 

 presence of infected sheep to one familiar with the character of the 

 infection, even before noticing the animals. 



" The invasion of the necrotic process may continue until ligaments, 

 tendons, and even the bones are attacked, but before this final stage 

 is reached nature will attempt to repair the damage. 



FIG. 118 



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1 



Leg-and-lip disease in sheep. Infection with Bacillus necrophorus. (Dolan.) 



"The hoof of a sheep suffering from a chronic case of foot-rot 

 grows out rapidly and becomes very hard. It will often be found 

 with the toes so thickened and lengthened that the front part of the 

 foot is raised above its natural incline and the tendons at the heel 

 are subjected to additional strain, all of which tends to increase the 

 lameness and the awkwardness in gait of the victim. These thickened 

 and elongated toes will frequently be seen to have attained an added 

 length of three or even four inches, and they curl up like sled runners, 

 greatly interfering with the progression of the animal. 



" The course of this disease is slow and protracted, usually starting 

 with one foot and subsequently involving one or more of the others. 

 During this interval it will probably spread to the feet of other sheep, 



