SEXUAL DIMORPHISM OF THE DOG HEPATOID CIR CUMANAL GLANDS AND ITS TIME-RELATED CHANGES

The histology of sexual dimorphism of the dog hepatoid circumanal glan ds has not been studied before. Studies of hepatoid and other skin gla nds of the circumanal region of adult dogs and puppies (1 and 38 days) of both sexes have shown striking differences in the structure of thi s region in adult males and females and complete qualitative similarit y in puppies of the both sexes. The hepatoid glands of adult males for m a massive glandular layer comprising 91.% of the skin thickness and supplanting all other glandular types. In adult females these glands a re reduced to widely spaced islets (12% of the skin thickness), and th e apocrine glands are the prevailing glandular type (53%). The hepatoi d glands of puppies of the both sexes develop according to the same st ructural scheme, approaching rapidly to the glands of adult males. In female puppies they develop more rapidly, and at the age of 38 days th eir absolute size (length of glandular lobes) is already thrice that o f adult females. The hepatoid glands of adult females undergo a very s ignificant regress and possess several structural features suggesting their degeneration.