Elaphostrongylus odocoilei n. sp.,a New Lungworm in Black Tail Deer (Odocoileus columbianus). Description and Life History

Abstract

During the examination of about 100 Black Tail deer of the California Coast Range approximately 25 were found to be affected with a lungworm-disease as yet unknown among ruminants. Heavily infested lungs showed macroscopically the picture of an induration. Microscopically this was found due to innumerable small nodules, invisible to the unaided eye. Each tubercle ordinarily enclosed several eggs of a nematode or embryos or both. In no case could adult stages be found, either in the parenchyma or in the blood vessels of the lungs. The regular distribution of the nodules on the other hand indicated that an embolisation of the eggs had taken place. Larvae, of course, were present in large numbers throughout the tubulous system of the lungs.

In a single case 2 adult nemas could be seen twisted around a trabecle of the right pro ventricle of the heart, thus indicating that the regular localization of the worms was distant from lungs and heart.

Finally, eggs as well as the nematodes themselves could be detected embedded in the connective tissues of the vessels beneath the spine and their nearby branches. They could be extracted even from between the muscles surrounding the body cavity and from along the vessels of the upper part of the hind legs. No traces of the worms, however, or of the eggs were seen on the subcutaneous tissue of the entire body, nor between the muscles of the head, neck, and frontlegs, nor between the mesenterium. Ordinarily they were coiled up in the lymphatic spaces of the connective tissue. Several specimens, however, were secured which had penetrated the wall of larger venous vessels of the hind legs.

The nematodes presented different stages of growth. Sexual larvae have as yet not been found. Worms recovered from the subserosa were usually smaller than those found in remote muscles. Inconspicuous accumulations of hemoglobin or hemosiderin deposited under the peritoneum or small hemorrhages between the connective tissue of the muscles together with the brown colored intestine of the worms were sometimes of assistance in the detection of the minute nematodes.