392 Veterinary Medicine. 



in expectoration. Treatment and prevention : Restrict to boiled -water, 

 salted meat ; oil of turpentine, arsenic. 



The dog harbors a variety of worms in the lungs, which may 

 give rise to similar pathologic phenomena. 



Strongylus vasorum. A delicate, cylindroid worm smaller 

 toward the ends, male )4 inch, female yi inch long, whitish or 

 pink and having an interrupted reddish spiral representing the 

 digestive canal shining through the skin. Head with two alas ; 

 mouth round, naked, terminal. Male has caudal membrane in 

 two lobes each having four rays, the anterior and third bifid, the 

 second and fourth simple. Two equal spicula. Female with 

 blunt, slightly curved tail, and vulva near its tip and close in 

 front of the anus. Ova elliptical. 



Habitat. Cavities of the heart and pulmonary blood vessels of 

 the dog. 



History. Lesions. These were found by Dujardin in 1812 in 

 the heart of a dog at Paris. Serres records the death of a dog 

 from an immense number of these worms in the right auricle and 

 blocking the pulmonary artery even to its smallest divisions. In 

 the heart they seem to find shelter in the recesses beside the col- 

 umnse carnse, where they cause erosion of the endocardium, granu- 

 lations and fibrinous deposits and clots. The embryos are found in 

 the bronchia as has been demonstrated by I,aulanie. The ova, 

 laid in the pulmonary artery and its branches, are arrested in the 

 arterioles and capillaries, and there the two embryos are hatched 

 out and in part escape into the air tubes. The irritation caused 

 by the ova and embryos in the capillaries, determines active cell 

 proliferation and the formation of a semi-transparent nodule, like 

 a miliary tubercle, consisting of embryonal and epithelial cells 

 with the ova or worms in the centre. 



The general aspect of the affected portion of the lung is a pearly 

 gray, but with a lens the distinct granules can be seen and by 

 teasing out one of these the ova and embryos can be detected un- 

 der the microscope. In this way these granules may be easily 

 distinguished from genuine miliary tuberculosis. 



Laulanie deduced from experiments in feeding the infested 

 lungs, that the expectorated embryos are taken in by other dogs 

 in food or water, and undergo partial development in the digestive 

 organs or veins, so that they can attain maturity in the heart 

 and pulmonary artery. 



