Arteriovenous anastomoses in the skin of tropical cattle.

As part of a general study of the vascular arrangement in the skin of cattle in tropical environments, the arteriovenous anastomoses (AVA) and other specialized vascular structures in the various skin sites of cattle were observed histologically. AVA were abundant in the skin from the scrotum, eye margin and the lower limb sites but were generally less numerous on the hairy body skin sites of cattle. Most of the AVA, especially those in the scrotal skin, were complex and tortuous S-shaped vessels, mainly located in the mid- and lower reticular layer and the mid- and lower papillary layer. The possible significance of their presence in various body sites, especially on the scrotal skin, is discussed.