Furunculosis is a deep form of infection, often occurring together with bacterial folliculitis. It most commonly occurs in the hairless skin around a German Shepherd's anus. The condition is first noticed when an affected dog licks its bottom more. When examined the area is inflamed and often ulcerated with variably sized open wounds. Tracks penetrate deep into the perianal tissue. Anal furunculosis is very uncomfortable for affected dogs. The tail may be elevated and the bottom licked or bitten. Some dogs are faecally incontinent. Others strain but pass no faeces. The region can be very smelly. Although this painful condition occurs primarily in German Shepherds in may also occur in other breeds if individuals are immune-compromised, usually at between four and seven years of age. It is unknown in cats.
Although bacterial cultures reveal common causes of pyoderma such as Staphylococcus intermedius or opportunist bacteria such as Proteus, Pseudomonas or E. coli, this condition seldom responds to antibiotics alone. Antibiotics in conjunction with corticosteroids will eventually control the condition in many dogs although treatment is usually necessary for months. We use the immunosuppressive drug cyclosporin to successfully treat anal furunculosis.