DISEASES OF HORSES AND CATTLE. 18S 



CHAPTER XV. 



BLACK LEG (INFLAMMATORY FEVER). 



In the Veterinarian, February, 1880, Dr. Green- 

 field's lecture on this disease says: "This disease 

 did not appear in healthy animals inoculated with 

 black leg virus, and no bacteria was found in the 

 blood of animals affected with this disease, which 

 shows that it is not an anthrax disorder, but is 

 brought on by the kind of food the animal is fed 

 upon. Cattle of all ages are liable to become af- 

 fected, but young stock appear to be most readily 

 so; six-month-old calves and up to two years, seem 

 to be those usually affected when changed from a 

 poor pasture to a rich, especially low-lying lands. 

 Such animals fatten with rapidity and soon attain 

 a high state of plethora, when perhaps some of 

 them become lame. Stop feeding and soon a 

 swelling appears in some part of the body, espe- 

 cially about the hocks or stifle. It is hot and very 

 painful, and is often mistaken for an injury. If 

 at first it was painful, the pain soon leaves, and it 

 becomes insensible, and if cut with a knife, a little 

 watery black blood will exude. The part has be- 

 come gangrenous, cold, and crackles on pressure 

 as if it was full of air. This is caused by the forma- 

 tion of gas from the decomposition of the blood. 

 Later on, when the swellings are cut into there will 



