Perianal fistula

What is ... ?: 

 Perianal fistula is a painful, chronic condition in which single or multiple ulcerated tracts develop in the tissue around the anus. No one clear cause has been established, although many have been considered. Some of the factors involved appear to be a broad tail base and low tail carriage, and an increased density of sweat glands in the anal region. It is these sweat glands that become inflamed and infected, leading to the draining sinus tracts typical of this condition.

How is ... inherited?: 

unknown, but there is a strong breed predisposition for the breeds mentioned below.

What does ... mean to your dog & you?: 

 This condition is painful for your dog. The types of signs you will see include straining or pain with defecation, bleeding, constipation, fecal incontinence, licking of the area, and malodorous anorectal discharge. These signs worsen as more tissue in the area around the anus becomes affected.

How is ... diagnosed?: 

 Diagnosis is usually straightforward, based on your description of what you observe in your dog, and on physical examination in which your veterinarian will find single or multiple areas of ulceration and draining tracts, with pus and blood. Your veterinarian may also take a skin biopsy if s/he suspects a tumour in the area (which usually has a more raised appearance, but can also be associated with extensive ulceration).

How is ... treated?: 

 This is a difficult condition to treat. Medical treatment (combination of antibiotics, antiseptics, and anti-inflammatory drugs) only provides temporary relief, and is usually not successful in clearing up the condition. Generally surgery is required, and there are several methods used including surgical removal of the tracts, freezing or cautery of the tissue, and tail amputation. Possible post-operative complications include significant bleeding, fecal incontinence, and recurrence of the tracts.

In mild cases, surgery often results in complete resolution of the problem, without recurrence. Where the problem is more severe (more tissue destruction), there is a lower rate of success and a higher occurrence of complications. Your veterinarian will discuss all this with you when considering what is best for your dog.

Breeding advice: 

 Although the inheritance (or even the cause of the condition) is not understood, it is preferable not to breed affected animals.



What breeds are affected by ... ?