Abstract
In previous communications 1 , 2 , 3 the writer has demonstrated a method whereby dogs may become infected with canine and human strains of Endamoeba histolytica. He has also proved that the dog is a particularly appropriate animal for study of amebic enteritis, since it is readily infected and manifests all of the symptoms described for human intestinal infections with this organism. Moreover the lesions in the large bowel are similar to those found in man. The present paper is based on an analysis of the protocols of 77 dogs which have been inoculated with the pathogenic ameba and on which careful observations have been made.
The essential data are set down in Table I. Eleven strains of the organism have been used, 2 of canine origin and 9 of human origin. There is also evidence that 8.4% of the positive cases were detected post mortem and that 12.7% of the animals which were positive at one time or another during their life failed to show any gross or histological post mortem evidence of infection.
The great majority of these animals were inoculated by the intrarectal tubal method. 2 Eight received the inoculum in the form of cysts by mouth. The number of inoculations utilized and the relative proportions of “takes” by each route is set down in Table II. It is evident that a single inoculation is usually sufficient (in 72.7% of the cases) to produce infection.
Slightly more than half of the dogs died of a primary amebic enteritis. The intercurrent diseases which were primarily responsible for the death of the other animals are indicated in Table III. However, it would be erroneous to assume that similar infections did not play an important role in those succumbing to amebiasis, since it is hardly possible to obtain an animal from the streets without one or more pathogenic infections.
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