UDDER-TUBERCULOSIS 99 



Frequently secondary pyobacillosis develops wherein 

 the organisms which produce an effect similar to that of the 

 tubercle bacilli in general concur in the destruction of the 

 udder. 



I have never observed a secondary infection with actino- 

 mycosis. 



Once I observed a secondary infection with an organism 

 closely allied to the diphtheria bacillus (and b. pyoneph- 

 ritidis bovis ) . The bacillus was Gram positive, moderately 

 large, and when grown on coagulated blood serum showed 

 granular inside bodies capable of taking a deep stain. Cul- 

 tures in serum-gelatin-agar plates, stab serum-gelatin-agar, 

 coagulated blood-serum, and in milk and bouillon were 

 like the diphtheria bacillus, yet no pellicle was formed on 

 the surface of the bouillon. One cubic centimetre of an 

 eight-day bouillon culture injected subcutaneously killed 

 a guinea-pig by intoxication. 



In addition to numerous small tuberculous foci near the 

 base of the teats the udder presented five grayish-red firm 

 necrotic foci ranging in size from a hazelnut to a walnut 

 and surrounded by a connective-tissue capsule. Besides 

 tubercle bacilli, these nodules showed a great number of 

 the above-mentioned bacilli. I have never seen this con- 

 dition occur as a single infection of the udder. 



Secondary Infection Through Wounds. — These sec- 

 ondary infections occur from a primary wound or from a 

 secondary wound produced by ulceration. Such wounds 

 produced by tuberculous ulceration are rare, however. 



These secondary infections may be streptomycosis, sta- 

 phylomycosis, colibacillosis and pyobacillosis. They may 

 occur separately or several together. 



Staphylomycosis liquefies the necrotic area and conse- 

 quently induces an infectious softening. 



Saprophytic invasion can cause milk-gangrene and 

 wound-gangrene. 



