Perianal Fistulas

What are Perianal Fistulas?
Also known as anal furunculosis, perianal fistulas are painful, inflamed tunnel-like formations that reach deep into the area surrounding the anus. It is a chronic and progressive disease.

How does my dog get Perianal Fistulas?
The condition is believed to have an immune-mediated component. It may also be related to the conformation of the tail around the anal area, where the tail resting tightly to the body creates a warm moist area, allowing bacteria to multiply. The sebaceous glands in the area become infected, abscesses form, then open and drain.

How do I know if my dog has Perianal Fistulas?
Middle-aged intact male German Shepherds are especially suspect. Your dog may chew or lick at the area around his anus excessively, or scoot his rear along the floor. He may have problems associated with bowel movements, such as pain, constipation, diarrhea, or blood in the stool. The area around the anus may be inflamed, bloody, and have a bad-smelling discharge. Later, the area may become darkened.  Because of the pain associated with the fistulas, the dog may not want to play or interact, and even lifting his tail may cause him a lot of pain. Your veterinarian will examine the area, but may have to sedate him because it can hurt so much to probe the area. A biopsy of the area will confirm the diagnosis.

What can I do about Perianal Fistulas?
Un-neutered males have a higher prevalence. Thus, neutering is one suggestion for prevention.   Mild conditions may be treated by clipping the hair in the area and cleaning it with antiseptic wash and hydrotherapy in which large amounts of water are used to flush the area. More severe cases are treated with immunosuppressive drugs given for several weeks. This therapy has a good success rate, but if it's not successful, surgery to remove the diseased tissue may also be needed. At one time tail amputation was suggested in order to afford better ventilation to the area, but it is only a last resort.

Is there anything I can do to prevent my dog from getting Perianal Fistulas?
If you have a German Shepherd, or any breed with a hanging tail, check the area under the tail and around the anus frequently. Do not allow it to remain moist; if need be, shave, wash and dry the area. If your dog has signs of perianal fistulas, have your veterinarian examine him and begin treatment as soon as possible. Treatment has a better success rate, with less recurrence, when begun early.

Are there certain breeds that get Perianal Fistulas more often?
German Shepherds have the highest incidence, but the condition has also been reported in Irish Setters, Labrador Retrievers, Old English Sheepdogs, Border Collies, Bulldogs, and some spaniels.