Localization and associated histopathology of asexually proliferative Mesocestoides corti tetrathyridia (cestoda) infecting mouse mammary glands

Female mice of pregnant random-bred, or unmated BALB/c groups were exposed per os to Mesocestoides corti tetrathyridia and necropsied at various intervals postexposure. The right posterior subcutaneous fat pad with two mammary glands was removed from each mouse, stained, mounted whole and examined microscopically for localization of worms. The left fat pad/gland set was processed, sectioned and stained using standard histological techniques. In pregnant mice, tetrathyridia were localized primarily in the fat pad's posteroventral lobe. Unmated mice had few worms in the mammary glands or associated fat pads. The difference in infection levels between the two host groups may result from mouse strain difference or the pregnant condition of one group.