INFECTIOUS DISEASES OP CATTLE. 461 



the infected area are infiltrated with a yellow gelatinous material con- 

 taining an orange-colored foam, due to the presence of gas bubbles. 

 The muscles at this point are friable, spongy, and of a uniform brown- 

 ish tint, disassociated by gas and a blood-tinged exudate. This gan- 

 grenous tissue, when present before death, can be removed without 

 pain to the animal. The intestines are generally normal, but they, 

 together with the peritoneum, may be inflamed, and the lungs are 

 iisually the seat of an edema. The spleen, liver, and kidneys retain 

 their normal appearance, in marked contrast with anthrax. 



Differential diagnosis. — Unlike blackleg this disease never appears 

 as an epizootic but in isolated cases. It may also be differentiated 

 from the former by the history of a recent parturition or surgical 

 operation, by the presence of an external injury at the site of the swell- 

 ing accompanied by a fetid liquid discharge, and the gangrenous 

 appearance of the tumefaction. Man is susceptible to malignant 

 edema, but not to blackleg. Malignant edema may also be easily dif- 

 ferentiated from .anthrax in that the blood and spleen are normal in 

 appearance, while in the latter disease the blood is dark and of a tar- 

 like consistency and the spleen appears swollen, injected, and softened. 

 The local tumor in malignant edema contains gas bubbles, while in 

 anthrax swellings these are absent. Inoculation experiments of guinea 

 pigs, rabbits, and chickens will also disclose the differences among 

 the above three diseases, since all of these species are killed by the 

 germ of malignant edema, only the first two species by the anthrax 

 bacillus, while the guinea pigs alone will succumb to the blackleg 

 infection. 



Treatment. — Treatment is chiefly surgical and consists in laying 

 the infected areas wide open by free incision, followed by a liberal 

 application of a 30 per cent solution of hydrogen dioxide and subse- 

 quently a 5 per cent solution of carbolic acid. Usually the disease 

 when observed has advanced to such an extent that medicinal inter- 

 ference is without avail. Preventive treatment is by far the most 

 desirable, and consists, essentially, in a thorough disinfection of all 

 accidental and surgical wounds, the cleansing of the skin, and the 

 exclusion of soil, filth, and bacteria during surgical operations of any 

 nature. Sheds, barns, and stables should receive a thorough applica- 

 tion of quicklime or crude carbolic-acid wash after all rubbish has 

 been removed and burned. All animals should be burned or deeply 

 buried and covered well with quicklime. 



SOUTHERN CATTLE FEVER (TEXAS FEVER). 

 (Pis. XLVI to IS, inclusiye.) 



This disease, which is more commonly known as splenetic, or Texas, 

 fever, is a specific fever communicated by cattle which have recently 

 been moved northward from the infected district, or which is con- 

 tracted by cattle taken into the infected district from other parts of 



