Shabadash S A, Zelikina T I
Izv Akad Nauk Ser Biol. 1995 Sep-Oct(5):590-605.
The histology of sexual dimorphism of the dog hepatoid circumanal glands has not been studied before. Studies of hepatoid and other skin glands of the circumanal region of adult dogs and puppies (1 and 38 days) of both sexes have shown striking differences in the structure of this region in adult males and females and complete qualitative similarity in puppies of the both sexes. The hepatoid glands of adult males form a massive glandular layer comprising 91% of the skin thickness and supplanting all other glandular types. In adult females these glands are reduced to widely spaced islets (12% of the skin thickness), and the apocrine glands are the prevailing glandular type (53%). The hepatoid glands of puppies of the both sexes develop according to the same structural scheme, approaching rapidly to the glands of adult males. In female puppies they develop more rapidly, and at the age of 38 days their absolute size (length of glandular lobes) is already thrice that of adult females. The hepatoid glands of adult females undergo a very significant regress and possess several structural features suggesting their degeneration.