INFECTIOUS DISEASES 



279 



back and forth and exchanging labor are prolific means of carrying 

 infection from place to place. Careless veterinarians have in some 

 instances apparently been responsible for the transmission of hog 

 cholera from infected to non-infected premises. 



Fig. 73. Large intestine of hog showing small lentil-sized ulcers, a con- 

 dition frequently associated with hog cholera. (Ostertag.) 



The possibility of insect transmission of the filtrable virus should 

 not bef overlooked. According to experiments conducted by the 



iButton-like sloughing of the mucosa U'cers of the mucosa 



Fig. 74. Large intestine of hog showing extensive alterations, a con- 

 dition frequently associated with cholera. (Ostertag.) 



Bureau of Animal Industry and reported by Dorset, hog cholera 

 was transmitted by house flies that had consumed the nasal or ocular 

 discharges of cholera infected swine and were then transferred to 



