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Anal Furunculosis
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Why Should I bring my Pet to Willows for Anal Furunculosis?
Willows is one of Europe’s leading small animal referral centres. Our state-of-the-art hospital is led by internationally renowned Specialists who are committed to providing the highest standards of veterinary care. The Dermatology service at Willows is led by Certified European Specialist Jon Hardy who has extensive experience of diagnosing and managing cases of anal furunculosis.
Our Dermatology service is supported by our multi-disciplinary team of Specialists across a number of disciplines including; Internal Medicine and Soft Tissue. In addition, Willows has a large dedicated team of Nurses and clinical support staff available 24 hours a day, every day of the year to provide the best possible care for your pet.
willows-cardiology-icon
Why Should I bring my Pet to Willows for Anal Furunculosis?
Willows is one of Europe’s leading small animal referral centres. Our state-of-the-art hospital is led by internationally renowned Specialists who are committed to providing the highest standards of veterinary care. The Dermatology service at Willows is led by Certified European Specialist Jon Hardy who has extensive experience of diagnosing and managing cases of anal furunculosis.
Our Dermatology service is supported by our multi-disciplinary team of Specialists across a number of disciplines including; Internal Medicine and Soft Tissue. In addition, Willows has a large dedicated team of Nurses and clinical support staff available 24 hours a day, every day of the year to provide the best possible care for your pet.
What is Anal Furunculosis?
What Causes Anal Furunculosis?
Anal furunculosis is a chronic, progressive inflammatory disease of dogs that results in ulceration and inflammation in the area surrounding the anus. Anal furunculosis occurs most commonly in middle aged or old aged German shepherd dogs, although other breeds can be affected.
There are a number of theories that have been proposed over the years regarding the cause(s) of anal furunculosis. These include the presence of a wide-based tail and increased numbers of sweat glands in the region of the anal canal. However, recent research has found a number of similarities between anal furunculosis in dogs and a condition called Crohn’s disease in humans. Analysis has suggested that anal furunculosis lesions develop due to a lack of some of the immune system’s defences that would usually protect the intestines and perineal skin from the bacteria normally present in that area. A separate part of the immune system is then exposed to more bacteria than normal and becomes over-activated. This over-activation of certain components of the immune system leads to marked inflammation and ulceration of the local area.
What is Anal Furunculosis?
What Causes Anal Furunculosis?
Anal furunculosis is a chronic, progressive inflammatory disease of dogs that results in ulceration and inflammation in the area surrounding the anus. Anal furunculosis occurs most commonly in middle aged or old aged German shepherd dogs, although other breeds can be affected.
There are a number of theories that have been proposed over the years regarding the cause(s) of anal furunculosis. These include the presence of a wide-based tail and increased numbers of sweat glands in the region of the anal canal. However, recent research has found a number of similarities between anal furunculosis in dogs and a condition called Crohn’s disease in humans. Analysis has suggested that anal furunculosis lesions develop due to a lack of some of the immune system’s defences that would usually protect the intestines and perineal skin from the bacteria normally present in that area. A separate part of the immune system is then exposed to more bacteria than normal and becomes over-activated. This over-activation of certain components of the immune system leads to marked inflammation and ulceration of the local area.
What is Anal Furunculosis?
Anal furunculosis is a chronic, progressive inflammatory disease of dogs that results in ulceration and inflammation in the area surrounding the anus. Anal furunculosis occurs most commonly in middle aged or old aged German shepherd dogs, although other breeds can be affected.
What Causes Anal Furunculosis?
There are a number of theories that have been proposed over the years regarding the cause(s) of anal furunculosis. These include the presence of a wide-based tail and increased numbers of sweat glands in the region of the anal canal. However, recent research has found a number of similarities between anal furunculosis in dogs and a condition called Crohn’s disease in humans. Analysis has suggested that anal furunculosis lesions develop due to a lack of some of the immune system’s defences that would usually protect the intestines and perineal skin from the bacteria normally present in that area. A separate part of the immune system is then exposed to more bacteria than normal and becomes over-activated. This over-activation of certain components of the immune system leads to marked inflammation and ulceration of the local area.
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How is Anal Furunculosis Diagnosed?
Anal furunculosis is usually diagnosed by clinical examination. Clinical signs include pain, particularly whilst passing faeces, a foul odour around the bottom, matting of fur and discharge around the bottom and red, ulcerated and sore-looking skin around the anus.

Examination may require sedation or general anaesthesia as it can be a little uncomfortable. This also allows thorough clipping of the hair surrounding the lesions, as well as cleaning of the area and documentation of the extent and distribution of the lesions. This initial assessment is invaluable in allowing monitoring of progress during subsequent treatment.
How is Anal Furunculosis Diagnosed?
Anal furunculosis is usually diagnosed by clinical examination. Clinical signs include pain, particularly whilst passing faeces, a foul odour around the bottom, matting of fur and discharge around the bottom and red, ulcerated and sore-looking skin around the anus.

Examination may require sedation or general anaesthesia as it can be a little uncomfortable. This also allows thorough clipping of the hair surrounding the lesions, as well as cleaning of the area and documentation of the extent and distribution of the lesions. This initial assessment is invaluable in allowing monitoring of progress during subsequent treatment.
How is Anal Furunculosis Diagnosed?
Anal furunculosis is usually diagnosed by clinical examination. Clinical signs include pain, particularly whilst passing faeces, a foul odour around the bottom, matting of fur and discharge around the bottom and red, ulcerated and sore-looking skin around the anus.

Examination may require sedation or general anaesthesia as it can be a little uncomfortable. This also allows thorough clipping of the hair surrounding the lesions, as well as cleaning of the area and documentation of the extent and distribution of the lesions. This initial assessment is invaluable in allowing monitoring of progress during subsequent treatment.
What Treatments are Available for Anal Furunculosis?
The first line treatment for this disease involves drug therapy. In the majority of cases this will dramatically shrink the lesions and may clear them up completely. If the lesions shrink but remain present, the option of surgery to try to remove the remaining ulcerated areas may be discussed. A proportion of the patients whose lesions resolve following medical management or surgery can suffer relapses.

Currently, the oral drug ciclosporin is the treatment of choice for anal furunculosis, this drug reduces the activity of the immune system cells. Other options include immunosuppressive drugs like azathioprine and prednisolone (a steroid), but these drugs are a little less specific in their action and less effective.

Once medical therapy has started, regular checks will be necessary to assess the tolerance of a patient to the medication, and also to chart the progress of the disease. This usually involves regular visits to the vet and examination of the anal area (possibly under sedation or general anaesthesia). Blood samples to check liver and kidney function might also be needed depending on the drug being used.

Some cases are not controlled satisfactorily with medication. In such instances, surgery is usually considered to remove the remaining lesions once they have been shrunk as much as possible with drug therapy. The surgery generally involves removal of the active lesions and some of the scar tissue as well as the anal glands from one or both sides. Sometimes it is necessary to stage the procedure, by performing surgery on the second side once the first has had time to heal. Surgical removal of persistent lesions can offer the chance of cure to those cases that have not been controlled by medical therapy.
What Treatments are Available for Anal Furunculosis?
The first line treatment for this disease involves drug therapy. In the majority of cases this will dramatically shrink the lesions and may clear them up completely. If the lesions shrink but remain present, the option of surgery to try to remove the remaining ulcerated areas may be discussed. A proportion of the patients whose lesions resolve following medical management or surgery can suffer relapses.

Currently, the oral drug ciclosporin is the treatment of choice for anal furunculosis, this drug reduces the activity of the immune system cells. Other options include immunosuppressive drugs like azathioprine and prednisolone (a steroid), but these drugs are a little less specific in their action and less effective.

Once medical therapy has started, regular checks will be necessary to assess the tolerance of a patient to the medication, and also to chart the progress of the disease. This usually involves regular visits to the vet and examination of the anal area (possibly under sedation or general anaesthesia). Blood samples to check liver and kidney function might also be needed depending on the drug being used.

Some cases are not controlled satisfactorily with medication. In such instances, surgery is usually considered to remove the remaining lesions once they have been shrunk as much as possible with drug therapy. The surgery generally involves removal of the active lesions and some of the scar tissue as well as the anal glands from one or both sides. Sometimes it is necessary to stage the procedure, by performing surgery on the second side once the first has had time to heal. Surgical removal of persistent lesions can offer the chance of cure to those cases that have not been controlled by medical therapy.
What Treatments are Available for Anal Furunculosis?
The first line treatment for this disease involves drug therapy. In the majority of cases this will dramatically shrink the lesions and may clear them up completely. If the lesions shrink but remain present, the option of surgery to try to remove the remaining ulcerated areas may be discussed. A proportion of the patients whose lesions resolve following medical management or surgery can suffer relapses.

Currently, the oral drug ciclosporin is the treatment of choice for anal furunculosis, this drug reduces the activity of the immune system cells. Other options include immunosuppressive drugs like azathioprine and prednisolone (a steroid), but these drugs are a little less specific in their action and less effective.

Once medical therapy has started, regular checks will be necessary to assess the tolerance of a patient to the medication, and also to chart the progress of the disease. This usually involves regular visits to the vet and examination of the anal area (possibly under sedation or general anaesthesia). Blood samples to check liver and kidney function might also be needed depending on the drug being used.

Some cases are not controlled satisfactorily with medication. In such instances, surgery is usually considered to remove the remaining lesions once they have been shrunk as much as possible with drug therapy. The surgery generally involves removal of the active lesions and some of the scar tissue as well as the anal glands from one or both sides. Sometimes it is necessary to stage the procedure, by performing surgery on the second side once the first has had time to heal. Surgical removal of persistent lesions can offer the chance of cure to those cases that have not been controlled by medical therapy.
What can I Expect if my Dog is Diagnosed with Anal Furunculosis?
At least 95% of cases will significantly improve following medical therapy, with lesions reducing in size between 60% and 100%. Drug therapy usually lasts from 4-24 weeks with most patients responding within 12 weeks. Up to 85% of patients go into complete remission (lesions disappear) using medical therapy but approximately 40% of these cases can suffer recurrence of the disease. If recurrence occurs it usually does so within six to eight months after treatment is stopped. These cases suffering from recurrence often respond to additional courses of medical therapy. Approximately 4% of cases do not significantly improve with medical therapy.

Surgery is generally reserved for the cases that continue to suffer from lesions despite medical therapy or those with frequent recurrences. Surgery is performed once the lesions are small enough to avoid the need for reconstructive skin closure techniques (plastic surgery). The success rates after surgery vary, but recent work suggests that in appropriately managed cases, 90% of dogs are cured. To achieve these success rates, careful patient management is required and this usually involves a period of lesion reduction using medication prior to surgery.
What can I Expect if my Dog is Diagnosed with Anal Furunculosis?
At least 95% of cases will significantly improve following medical therapy, with lesions reducing in size between 60% and 100%. Drug therapy usually lasts from 4-24 weeks with most patients responding within 12 weeks. Up to 85% of patients go into complete remission (lesions disappear) using medical therapy but approximately 40% of these cases can suffer recurrence of the disease. If recurrence occurs it usually does so within six to eight months after treatment is stopped. These cases suffering from recurrence often respond to additional courses of medical therapy. Approximately 4% of cases do not significantly improve with medical therapy.

Surgery is generally reserved for the cases that continue to suffer from lesions despite medical therapy or those with frequent recurrences. Surgery is performed once the lesions are small enough to avoid the need for reconstructive skin closure techniques (plastic surgery). The success rates after surgery vary, but recent work suggests that in appropriately managed cases, 90% of dogs are cured. To achieve these success rates, careful patient management is required and this usually involves a period of lesion reduction using medication prior to surgery.
What can I Expect if my Dog is Diagnosed with Anal Furunculosis?
At least 95% of cases will significantly improve following medical therapy, with lesions reducing in size between 60% and 100%. Drug therapy usually lasts from 4-24 weeks with most patients responding within 12 weeks. Up to 85% of patients go into complete remission (lesions disappear) using medical therapy but approximately 40% of these cases can suffer recurrence of the disease. If recurrence occurs it usually does so within six to eight months after treatment is stopped. These cases suffering from recurrence often respond to additional courses of medical therapy. Approximately 4% of cases do not significantly improve with medical therapy.

Surgery is generally reserved for the cases that continue to suffer from lesions despite medical therapy or those with frequent recurrences. Surgery is performed once the lesions are small enough to avoid the need for reconstructive skin closure techniques (plastic surgery). The success rates after surgery vary, but recent work suggests that in appropriately managed cases, 90% of dogs are cured. To achieve these success rates, careful patient management is required and this usually involves a period of lesion reduction using medication prior to surgery.