This is the second of a two-part report of an investigation to determine the response of baboons to Toxocara canis. The first report dealt with the white cell, serum protein, and antibody responses of infected baboons. The present paper describes the gross findings at autopsy, distribution of larvae, and the associated histopathologic response. Estimates of the number of larvae in the liver, lungs, brain, and heart were obtained by digestion of portions of these organs from four animals. In every instance greater numbers of larvae per gram of organ occurred in the liver. However, in three of the animals, roughly the same number of larvae were recovered per gram of lung tissue. Histologic studies suggested that the invading larvae migrated extensively through the liver during the first week of infection, producing considerable inflammation and necrosis, which was almost completely resolved by the 3rd week, coinicident with the height of intra-alveolar hemorrhage and edema in the lungs. Although this investigation was terminated prematurely because of an epidemic of tuberculosis, analysis of the various comparable data showed no apparent differences between two pairs of tubercular and nontubercular animals.
Present address: Department of Bacteriology and Parasitology, Baghdad University College of Medicine, Baghdad, Iraq.