736 Epizootic Lymphangitis. 



or pear-shaped structures in the pus of nodes and ulcers. 8ome of these Structures 

 were enclosed by mono- and polynuclear leucocytes, in the cell substance of which 

 karyosomes could be demonstrated with eosin-methylene blue, and which suggested 

 the appearance of Heliosoma tropicum, the cause of Oriental boil plague. Thiroux 

 & Teppaz failed in their attempts to cultivate the parasite, nor could they repro- 

 duce the disease by inoculation of the pus from the nodes. According to their 

 view, the leucocytozoons may be transported to the internal organs by means of 

 leucocytes and there set up their morbid process. 



Pathogenicity. After the administration of pus taken from 

 the nodes or ulcers into cutaneous wounds of solidungula, in- 

 flammation and swelling of the lymphatics may occur in rare 

 eases in the course of 20 to 60 days. Along the course of the 

 lymphatic vessels nodes develop which later form ulcers (Tixier, 

 Chauvrat, Delamotte, Peuch). In rabbits experimental infec- 

 tion produces local abscesses only, while in guinea pigs swelling 

 of the lips and the popliteal glands usually results. Other 

 experiment animals are immune. 



Natural infection probably occurs from superficial wounds 

 by immediate contact with infected objects (harness, litter, 

 bandages, instruments, etc.), or from contact of diseased ani- 

 mals with healthy ones. (Thiroux & Teppaz are of the opinion 

 that infection is spread through the medium of insects). The 

 ass is most susceptible, the horse and the mule less so while, 

 according to Tokishige's observations, cattle are also sus- 

 ceptible. 



Anatomical Changes. In the affected regions the skin and 

 subcutaneous connective tissue become thickened (up to 5 or 

 6 cm.) and firm; cross sections have a lardaceous appearance 

 and contain pus foci of various sizes, while the distended 

 lymphatics are filled with coagulated serum and pus, the walls 

 of these vessels being intensely reddened and having a finely 

 granulated appearance. The regional lymph glands are swollen 

 and frequently contain small pus foci or cicatrices which have 

 resulted from their presence. In the diseased joints we find 

 large masses of serous or sero-purulent exudate and the synovial 

 membranes are covered with villous proliferations; adjacent 

 tendons are much enlarged showing serous infiltration and 

 containing large pus cavities, in the internal organs (lungs, 

 testes, intestinal wall) metastatic pus foci are found only in 

 exceptional cases. The nasal mucous membrane is occasionally 

 swollen near the nostrils and contains on its surface sharply 

 circumscribed, flat, yellowish elevations as well as deep ulcers. 



Symptoms. Inflammation of the lymph vessels begins most 

 frequently on the limbs, especially the anterior ones, but is 

 observed also on the scrotum or the udder, somewhat rarely 

 on the abdomen and neck where they usually develop from a 

 wound or a fresh scar. Such wounds refuse to heal and grad- 

 ually form ulcers with red luxuriant granulations, or the re- 



