592 Veterinary Medicine. 



the presence of a pathogenic microbe in the stable, water, or 

 other part of the environment, the toxic products of which are 

 taken into the animal system. 



But as yet no specific pathogenic microbe has been demonstrat- 

 ed so that this doctrine must still be held as a mere plausible hy- 

 pothesis. 



Many veterinarians with long experience in such cases abso- 

 lutely deny contagion. The hypothetical contagion undoubtedly 

 extends slowly, and uncertainly from animal to animal, probably, 

 like actinomycosis, taking place mainly through the soil, or some 

 outside medium, rather than by direct contact ; or a special sus- 

 ceptibility on the part of the individual animal may be necessary 

 to render it effectual. 



Accessory Causes can be spoken of more confidently but even of 

 these no one, nor small group, can be advanced as essential. 

 The process of bone-nutrition is readily disturbed by a variety 

 of conditions, and such disturbances may easily become the 

 occasion of weakening the resisting power and mayhap of ad- 

 mitting the hypothetical microbe to get in its pathogenic work. 



Faulty food has been a favorite explanation. A lack of lime 

 in the soil and fodder seems, at times, to have had a baneful ef- 

 fect, if only, in lowering the general tone and impairing the 

 nutrition. Yet we see osteoporosis on limestone soils (New 

 York, etc.), and in animals generously fed on grain. The same 

 remarks apply to phosphorus and phosphates. Their deficiency 

 apparently contributes to the production of the disease, and yet 

 under other conditions, their abundance is no barrier to its de- 

 velopment. The excess of free phosphorus produces osteitis and 

 it is held by some that an over- abundance of phosphates acts in the 

 same way. It has been sought to incriminate a too nitrogenous 

 diet in some cases, and in others one too rich in fat or carbhy- 

 drates. The many cases in Philadelphia and Pennsylvania were 

 mostly in animals that had been well fed and were in good con- 

 dition when attacked (Marshall). 



Special food may be the direct cause, bran diet has been already- 

 noted. Hinebauch found an acute osteitis with bone softening 

 and arthritis in horses fed on millet, green, partially matured 

 and ripe. Horses elsewhere have fed on millet, without such 

 results, but not perhaps, in the same environment, nor ia 



