Anal furunculosis (also called perianal fistulas) is a distressing condition commonly affecting German Shepherd dogs and occasionally other breeds. The problem is one of chronic deep infection, inflammation, discharges and ulceration around the tail base and anus. The condition may progress to involve a large area around the back end of the dog.
It can be very difficult to cure or control but recent advances in treatments are proving encouraging.
What causes anal furunculosis?
No-one really understands what causes the condition to develop. It is more common in dogs with the broad tail base and low tail carriage typical of German Shepherds. This conformation may result in poor ventilation and increased humidity of the anal area. Faecal bacteria may persist in this environment increasing the risk of infection of hair follicles and hormone glands in this area. Underlying problems with the immune system may also play an important role. The disease has also been linked to inflammatory bowel disease and colitis. If your dog has diarrhoea they may be at more risk of developing anal furunculosis.
How would I know if my dog has anal furunculosis?
Anal furunculosis is very irritating and dogs with this condition will frequently lick their hind end. You may notice that your dog shows discomfort or difficulty when passing faeces. Other signs of illness such as weight loss irritability or depression due to pain are seen in severe cases. The tell-tale signs are of matted hair, odour, bleeding and discharges from the anal area. However your dog may not let you look closely if the condition is very painful. It should be possible for your vet to make a diagnosis of anal furunculosis from looking at the diseased area (but they may need to sedate your dog for close examination). In a few cases biopsies are needed to be certain of the diagnosis.
How is anal furunculosis treated?
This is a difficult disease to treat and although several types of treatment are available none is 100% effective. The diseased tissue can be removed at surgery – often, extensive treatment is needed and this may need to be repeated. If extensive surgery is performed there is a risk of nerve damage which can result in incontinence. Some surgeons advocate amputation of the tail to improve ventilation or removal of the anal sacs.
Recently, encouraging results have been achieved using drugs designed to alter the function of the immune system, and this may prove to be a very effective treatment for anal furunculosis.
Is there anything I can do at home to help in treatment?
Yes, check with your veterinary surgeon first, but many dogs with anal furunculosis are greatly helped by hydrotherapy. This involves the use of a shower attachment or garden hose to direct water over the affected area under the tail once or twice a day. The water should be lukewarm or cool, under moderate pressure. Start gradually and gently and build up as your dog gets used to this treatment. For this to be effective, each session should last at least 15 minutes. A tail bandage applied to the tail will stop this getting too wet. This treatment can have a very good effect if carried out diligently every day.
What is the outlook for a dog with anal furunculosis?
Controlling symptoms is a long-term process in many cases. New treatments are being developed, but relapses may occur and permanent treatment can be needed. Anal furunculosis is well known as a difficult and sometimes frustrating disease to treat. Recent treatments have shown encouraging results but euthanasia may need to be considered if your dog is very seriously affected or if your dog’s temperament makes home treatment difficult. More than most diseases, this one calls for a high level of commitment and extreme vigilance on the part of owners. Bear in mind that long-term treatment can prove expensive.
Whilst anal furunculosis can be a frustrating and difficult condition to treat it is important to seek help as soon as possible. If the condition becomes widespread it can be impossible to control. As there are a number of different treatment options it is important to discuss your dog’s problem with your own vet