428 Veterinary Medicine. 



Feeding hogs after Tuberculous Cattle. Where cattle and hogs 

 are kept on the same place, it is a common practice to let the 

 swine clean up all food left by the satiated cattle. If there are 

 tuberculous cattle, affected either in the air passages or ali- 

 mentary tract, the pigs become infected by taking in the expecto- 

 ration by which the food is soiled, or by rooting around where 

 the cow manure has fallen. 



Feeding from a Common Trough. In an infected herd, a 

 common cause of extension is found in the use by the whole herd 

 of a common feeding trough, in which the food soiled by viru- 

 lent discharges, is taken by healthy animals. The habit of tying 

 a cow in different stalls in succession as she happens to strike one, 

 in place of keeping each cow by its own stall is a fruitful source 

 of infection. Even when each cow is kept by its own stall, she 

 often becomes infected by reaching into the feeding trough in 

 front of the next cow on the left or right and taking in soiled 

 and infected fodder. In swill stables the evil reaches its maxi- 

 mum, as the feeding trough for 50 or 60 animals is slightly in- 

 clined so that the liquid food runs from the supply end to the 

 other, and infecting expectorations are carried in front of all in 

 turn. 



Dry, Dusty Stables. Tubercle bacilli are not carried out on 

 the expired air, unless there is forced expulsion as in coughing, 

 snorting or sniffing. In such cases the solid particles are thrown 

 off in masses or fine spray and lodged on surrounding objects. 

 These, together with infecting discharges from bowels, urinary 

 or generative organs, open sores, etc., dry up, and rise on the 

 dust, and, as sterilization occurs slowly indoors, they cause more 

 or less infection of the animal inmates. Cornet, Tappenier and 

 others have thoroughly established this as a common form of 

 transmission, and shown the great importance of cleanliness, dis- 

 infection and the removal of infecting materials without raising 

 dust. In an establishment in Paris, a consumptive had served 

 for 3 years. In the following 10 years, 15 of the 20 employes 

 died of phthisis. 



Extension through Vermin. As rats and mice (and other 

 rodents) are susceptible to tuberculosis by ingestion (Galtier) it 

 follows that they may become the media for extension of the 

 infection through fodder in which their droppings are scattered, 



