Jun 12, - Anal gland issues in pets are not fun, period! Cozmo began to have issues around the age of one. I first noticed the consistent, obsessive and. German Shepherd Dog (Alsatian) Related terms: Perianal fistula. Outline: German Shepherd dogs are predisposed to anal furunculosis, a condition in which there is inflammation and ulceration of the skin under the tail and around the anus, which can become severe with deep infection of underlying tissues. Brief.