428 CHRONIC INFECTIOUS DISEASES 



etc. It is also possible that insects may be carriers of the 

 infection. The disease is most common in cold, damp 

 weather. Asses and mules seem more predisposed than 

 horses. Cattle are very rarely affected. 



Symptoms. — The disease usually first attacks the limbs, 

 particularly the forelimbs, but may also occur on the scrotum 

 or udder, or more rarely the body and neck. Usually the 

 disorder originates in a wound or fresh cicatrix. A wound so 

 infected does not heal but is converted into an ulcer with 

 exuberant granulations. From a cicatrix a painful nodule 

 the size of a pigeon's egg forms, which later erupts, discharg- 

 ing a thick, yellow pus. Soon the inflammation involves 

 the lymph vessels, which become swollen, corded, and very 

 painful, and along their course fresh abscesses develop. 

 The abscesses rupture, forming ulcers which heal slowly. 

 The ulcers show a tendency to exuberant granulation, and 

 by confluence are spread and may produce great ulcerous 

 surfaces. The regionary lymph glands are involved in the 

 process; not infrequently abscesses form in them. As a 

 rule the infected limbs swell; particularly about the joints 

 and in the overlying skin superficial ulcers develop. 



In rare instances the morbid process may involve the 

 nasal mucous membrane, on which form white nodules and 

 later ulcers which tend to coalesce. The submaxillary lymph 

 glands are involved and may suppurate. Nasal discharge 

 is rare. Usually the appetite and temperature remain normal. 



Diagnosis. — The disease closely resembles skin glanders, 

 especially chronic cases. In doubtful instances the usual 

 tests for glanders may be applied. Otherwise a microscopic 

 examination of the pus from a true case of epizootic lymphan- 

 gitis will show the characteristic parasites. Ulcerous lym- 

 phangitis takes a much milder course and the pus contains 

 the characteristic bacillus. 



Course. — The , course is chronic. Mild cases last one or 

 two months. Remissions and exacerbations are not 

 uncommon. The mortality varies' from 7 to 10 per cent. 

 Patients which recover are usually left with thick legs. 



Treatment. — The treatment is largely surgical (extirpation 

 of the nodules, -early opening of abscesses, antiseptic treat- 



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