Perianal fistula, or anal furunculosis, is a serious medical condition that most commonly affects German Shepherd dogs, but may also occur in other pure bred or mixed breed dogs and is especially common in unsterilised males of middle age. Perianal refers to the area immediately surrounding the anus and a fistula is an abnormal connection or tunnel that forms between two tissues, organs, or vessels that normally do not connect. In affected dogs, the condition is usually associated with an infection in the perianal region, and there are usually one or more draining tracts present. The condition could be compared with a carbuncle – a many headed abscess which is why some veterinarians use the term furunculosis – a skin condition characterised by the development of recurring boils.
Perianal fistula: symptoms
Initially there may be few clinical signs and the condition may go unnoticed for some time. Sometimes, they are only discovered during a routine vet visit or during a grooming.
However, as the disease progresses, the dog will usually strain during defecation, and there will be blood in the faeces. A decreased appetite is common. The dog will also lick excessively at its tail and rectal regions. Some dogs will be reluctant to sit, some may not wag their tail normally, and some may become aggressive if the tail or hindquarters are touched. Behaviour changes are common. Some dogs will become withdrawn or act depressed, and others may appear agitated or even aggressive. If your dog demonstrates any of these signs, contact your veterinarian.
The causes of perianal fistulas
The cause is not fully understood although impaction or infection of the anal sacs (anal glands) and adjacent sinuses has been suggested. Poor air circulation around the anal regions also proposed as a major contributory factor. However, more recently it’s been suggested that the condition is more likely caused by an autoimmune disease. There also appears to be a genetic component to the condition, since some families of German Shepherd dogs appear particularly prone. One study indicates that approximately 80% of cases occur in German Shepherds.
Treatment
Treatment typically involves a combination of medical management and, in some cases, surgical interventions Cyclosporin is often the treatment of choice and early therapy can lead to better outcomes. if you suspect your dog may be suffering from this condition it is important to consult your vet asap.
