EPIZOOTIC LYMPHANGITIS 291 
Pearson describes its symptoms as follows: “The most common 
manifestation consists in the presence of small, chronic, discharging 
ulcers in the vicinity of the hock joint of a thickened hind leg. In 
such a case, one may also find small scars showing where ulcers have 
healed and there will probably be some firm nodules beneath the 
skin and, perhaps, one or more nodules that have softened, forming 
fluctuating abscesses. The regional lymphatic ducts are corded and 
the glands inside the thigh are hardened and nodulated. 
“The earliest observed symptom may be the occurrence of a 
firm nodule, from the size of a pea to that of a walnut, beneath 
the skin, anywhere on the body. Corded lymphatics extend from 
this lesion. In time, the nodule will soften and, at length, its purulent 
contents will break through the skin. The time required for these 
developments is most variable and may reach several weeks. Such 
pus is thick yellowish or greyish yellow and often is mixed with blood. 
Sometimes it contains flakes. 
“In other cases, the first symptom observed is an indolent sore, 
covered with pus and scab, surrounded by a slightly swollen zone 
and from which one or more firm cords extend beneath the skin 
toward the lymphatic glands. This condition is, no doubt, the 
first to develop, but such a sore often escapes special notice until 
nodules occur. 
“Fresh ulcers may be surrounded by a slightly raised zone of 
bright red granulation tissues (‘proud flesh’). The ulcers occur 
irregularly and they disappear slowly; some heal in a fortnight, 
others continue to discharge for months, and, after healing, may 
break out again. From this long continued irritation and from the 
formation of scar tissue, the skin thickens and the affected parts 
become indurated. 
“Ulceration sometimes occurs upon the conjunctiva and on the 
mucous membrane of the nostrils and upper respiratory tract.” 
Morbid anatomy. The lesions are an inflammation of the lym- 
phatics. On section the walls of the vessels are thickened, their 
internal membrane is congested, and the ducts filled with thick- 
clotted lymph mixed with pus, which is followed by the formation 
of the abscesses (pustules) and granulating sores. The affected parts 
become indurated as the result of the formation of fibrous tissue 
due to the inflammation set up by the disease. On the mucosa, the 
ulcers have a round, well-defined raised border. They are at first 
