Parasites of the Circulatory System. 405 



Diagnosis is completed by the discovery of the filaria. The 

 skin should be shaved as soon as the nodules appear, and on the 

 summit of each elevation will be seen an ecchymotic point. 

 When this spot is well developed, and before it has ruptured it is 

 laid open to a limited depth with a sharp scalpel, when the worm 

 will be detected in the act of drawing itself back into the deeper 

 layer of the skin, or subcutaneous connective tissue. Drouilly 

 advises to place a drop of oil of turpentine on the nodule and 

 watch the position and movements of the worm as manifested by 

 the ecchymotic streaks, or feel it as a firm cord under the tip of 

 the finger. It may sometimes be necessary to follow the line of 

 congestion and extravasation as deep as the muscles in order to 

 find the worm. When a nodule has subsided another may be 

 confidently looked for about J^ inch from the same point within 

 twenty-four hours. 



As a rule the general health is not seriously affected. The main 

 trouble is that the tender spots interfere with the harness. Yet 

 suppuration may occur (Lamy), and debility and death have 

 been reported for affected horses and mules (Brunswig, I^iautard). 



A speedy subsidence of the individual nodule is always to be 

 expected, and the tendency to further eruption disappears with 

 the advent of cold weather or winter. Though it recurs for sev- 

 eral years in succession on the coming of spring, yet in three or 

 four years a permanent recovery takes place, the parasite having 

 presumably reached the limit of its existence and perished. 



Treatment is mainly paliative, the affected part of the skin being 

 kept scrupulously clean by sponging, and friction by the harness 

 being carefully avoided. Rest may thus become essential. 

 Strong vermicide solutions like potassium sulphide, quassia, 

 wormwood, or naphthalin may be applied to the skin, and a gen- 

 erous diet and a course of tonics, such as arsenic may be desira- 

 ble. 



PILARIA MEDINENSIS. FILARIA OF MEDINA. DRACUNCULUS 



PERSARUM. 



The Guinea Worm, as this has been called, because of its 

 prevalence on the Guinea Coast, Africa, has been generally 

 treated as a parasite of man, and yet it has been repeatedly found 

 in the dog, the hor.se and even the ox. 



