558 DISEASES OF THE HORSE. 



utensils, harness, bandages, insects, etc. Solipeds are mostl}' sus- 

 ceptible, but cattle may also be infected. 



SyTnptoTns. — The inflammation of the lymph vessels is usually first 

 observed on the extremities, especially on one or both hind legs; it 

 may also appear on the forelegs, shoulder, or neck, and more rarely 

 on the rump, udder, and scrotum. The lesions, as a rule, develop in 

 the tissue adjacent to the place of inoculation. In the earh'' stages of 

 the disease the lymph vessels appear very hard and thickened, and 

 along their course hard nodules develop, ranging in size from a pea 

 to a hen's o^gg. Later these nodules soften, burst spontaneously, and 

 discharge a thick, yellowish pus. The surface of the resulting ulcers 

 or abscess cavities soon fills up with exuberant granulations which 

 protrude beyond the surface of the skin, giving it a fungoid appear- 

 ance. The affected extremities are considerably enlarged, similar 

 to cases of simple lymphangitis. In rare cases the mucous membrane 

 of the nostrils may also become affected, showing yellowish flat ele- 

 vations and ulcerations, and these may extend by metastasis to inter- 

 nal organs. In cases in which the mucous membrane is affected, the 

 submaxillary lymph gland may also become enlarged and suppurate. 



The constitutional symptoms accompanying this disease are not 

 very marked and may be altogether absent. There is usually only a 

 very slight fever, which seldom runs over 102° F. The appetite is 

 not impaired except in the advanced cases. 



Lesions. — The anatomical changes are most marked in the skin and 

 the subcutaneous tissues. They may become 2 to 3 inches thick and 

 indurated as the result of fibrous-tissue formation, owing to the in- 

 flammation present. On the baconlike cut surface suppurative areas 

 and granulating sores may be noticed of various sizes, also enlarged 

 lymph vessels filled with clotted lymph mixed with pus. The neigh- 

 boring lymph glands are usually enlarged and frequently contain 

 suppurating foci. Rarely the internal organs may show metastatic 

 abscesses. 



Dmgnosis. — The diagnosis is based on the characteristic appear- 

 ance of the ulcerations, which show exuberant .granulation of a bright 

 red color, inverted edges, and a thick, creamy, glutinous discharge. 

 These manifestations differentiate the disease from glanders, in which 

 the ulcers are craterlike, do contain exuberant granulations, and the 

 discharge is of a viscous, oily character. The submaxillary and 

 other nodes as well as the corded lymphatics in glanders are more 

 firmly attached to the adjacent tissues, and are therefore less mov- 

 able. In some chronic cases of sporotrichosis, however, the lesions 

 may closely resemble those of farcy, and in these cases the micro- 

 scopical examination of the pus will disclose the nature of the affec- 

 tion. In the pus the causative organism can be easily seen in the un- 

 stained specimen, and is recognized by its size, shape, and highly re- 



