FI LABIA IN THE BLOOD 1G7 



or blood penetrates into the cavity from the lungs in eases of some 

 traumatism of those organs. 



FILARIA IN THE BLOOD. 



Four kinds of parasites have l^een found in the lilood of the dog, 

 namely Filaria immltis, Hsematozoon lewisi, Strongylus vasorum, and 

 Spiroptera sanguinolenta. 



Filaria Immitis, Filaria Haematica. — (Males 10 cm. and females 35 

 cm. long; both 1.5 mm. thick.) They lie inside of the heart; very rarely 

 in the left, generally on the right, where they multiply in great num- 

 bers, often hundreds massed in a ball (Megnin) ; they are rarely found 

 in any other part of the vascular system; on the other hand, the eml^ryos 



Fig. 68. — Heart, with Filaria immitis in the ventricle (photograph) . 



measure 0.25 mm. long and 5 mm. thick, are found in the circulation in 

 hundreds of thousands and can be readily seen under the microscope in a 

 sample of blood of the affected animal (Delafond, Xocard, Gruby, Renther, 

 Johne, Rieck, Deffe, and others). The mature filarise living in the 

 heart (Fig. 68), cause disturbances of the circulatory system, dilatation 

 and hypertrophy of the heart, endocarditis, formation of thrombi with 

 all its results, and even rupture of the heart. The embryo may plug up 

 the small arteries particularly of the lungs, brain, and spleen. The em- 

 bryos seem to be excreted through the kidneys. This parasite is gener- 

 ally found in Indian, Chinese, and American dogs, especially in the south- 

 ern states. Wheeler rarely made a post-mortem that he did not find 

 it, often without presenting any observable symptoms during life. It is 

 rarely found in Europe. The clinical symptoms are not at all character- 

 istic — emaciation, epileptiform convulsions, disturbance of the heart ac- 

 tion, intestinal hemorrhage, and excitement — but frequently the filaria may 



