542 IOWA DEPARTMENT OF AGRICULTURE 



The different dips need not be discussed in this report, sheep 

 growers being well informed by Bureau reports upon formulas for 

 preparing and dipping sheep. 



NECROBACILLOSIS. 



The disease variously known as lip and leg ulceration, foot rot, 

 necrotic dermatitis, necrotic stomatitis, necrobacillis, etc., has in 

 recent years been widely disseminated, especially among sheep 

 in Wyoming and Montana, and some of the other western states. 



This disease known by experienced sheepmen as sore mouth, sore 

 lip, warty mouth, warty nose, ecthyma, stomatitis, etc., has pre- 

 vailed in this country, east and west, for twenty years or more. 

 Little effort was made to discover the causative agent or to check 

 the disease until recently. As yet, most writers on the subject have 

 not definitely determined the cause of the trouble, but a small 

 number have incriminated the bacillus necrosis. 



Sheepmen have customarily attributed the disease to coarse grass, 

 shad scale, bunch grass, clover, alfalfa, beet tops, frost and other 

 causes. 



The Bureau of Animal Industry has examined numerous speci- 

 mens during the past year and suceceded in isolating the necrosis 

 germ. The inoculation of lambs and older sheep with tissue from 

 diseased animals' mouths produced the disease. This fact alone 

 establishes the soundness of the germ theory stated. 



The disease is primarily caused by the necrosis germ. The pre- 

 disposing factor is the abrasion of the skin, allowing the access of 

 the causative organism. Prolonged drouth is often followed by 

 outbreaks of necrobacillosis. This is due probably to the fact that 

 the drouth necessitates closer foraging, inducing the sheep to 

 browse on thistles and roughage. Hard, dry scabs, warty in ap- 

 pearance, are produced, frequently covering the entire lips, which 

 when removed, leave a raw, granulated surface, with or without 

 an exudate of pus. This condition may be present at any stage 

 of the animal's growth. It is not caused, as is often supposed, 

 by the feed or the pasture, or the fact of recent weaning, but 

 these are predisposing causes. 



The disease affects calves, pigs, goats, adult cattle, horses, deer, 

 rabbits, dogs and chickens. It is transmissible from one species 

 to another. The Bureau of Animal Industry has observed a num- 

 ber of cases of transmission from one specie of animal to another. 



