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Perianal Fistula In Dogs

Perianal Fistula In Dogs

What Is Perianal Fistula In Dogs?

Perianal fistula (anal furunculosis) is a chronic, multifactorial, purulent, ulcerating, malodorous, sinus tract in the dog’s perianal region. An affected dog may have a single fistula or many fistulae that can surround the anal sphincter with deep open crevices and some oozing pus.

This disease is also called anorectal abscesses, pararectal fistulae, perianal fissures, perineal fistulae, and perianal sinuses.

Due to this condition’s similarity to a carbuncle (a cluster of boils or pus-filled bumps forming a connected area of infection), many vets prefer the use of the term furunculosis - a skin condition characterized by recurring boils with an accumulation of pus.

In affected dogs, the condition is usually associated with painful sinus tracts and ulcers that can encircle the anal opening.

Treatments range from medication to surgery, though for many dogs the problem peaks and valleys over time, and for some, this is a progressive condition.

Symptoms Of Perianal Fistula In Dogs

  • Experiencing pain when defecating.
  • Low tail carriage.
  • Skin irritation and redness around the anus.
  • Decreased Appetite (anorexia).
  • Constipation
  • Licking of the area.
  • Mucus or blood in his stools.
  • A smelly discharge.
  • Restless and Irritability.

Treatment Options For Perianal Fistula In Dogs

  • Medical management can be classified into 2 phases - an induction phase and a maintenance phase.
  • Medication managements are available but these approaches can be unsatisfactorily useful and frustrating for the pet owners and the pet.
  • As an autoimmune disease, the treatment focuses on restraining the immune reaction that is causing the condition and immunosuppressive drugs are suggested.
  • Surgery is only recommended for dogs when immunosuppression treatment has failed.
  • In milder cases, chemical cauterization of fistulae (chemical agents destroy abnormal tissue), Cryotherapy (a freezing agent is used to freeze and destroy abnormal tissue), and Laser therapy are used.
  • Almost 25% of cases are unresponsive and need intermittent treatment for life. The remaining 75% of cases resolve after lengthy treatment.
  • But in all the cases, although not curative, the treatment is certainly palliative and reduces the pain and discomfort that the dog experiences.
  • Cyclosporine- (brand name - Atopica) oral drug and tacrolimus - (used topically ) currently dominate immunosuppressive treatment for this condition.
  • Tacrolimus (brand name Protopic) and Azathioprineare also used nowadays.
  • Antibiotics are prescribed adjunctively to control complicating infections.

Home Remedies For Perianal Fistula In Dogs

  1. Calendula Compress: 1 cup of warm water, a tsp of salt, and 8 drops of calendula tincture, soak a cloth and apply it to the dog's bottom and make sure the region is dry after the procedure.
  2. Epsom Salt or Witch Hazel: 1 cup of warm water infused with 1 to 2 teaspoons of Epsom salt or Witch Hazel. Soak a cloth and hold this in the affected region for 5 to 10 minutes, twice per day, every day.

How To Prevent Perianal Fistula In Dogs?

  • A fiber-rich diet for your dogs is good.
  • Easily digestible foods avoid strain while stool passing.
  • Increase moisture by adding more liquid directly to their food.
  • Many dogs find moving water more pleasant. So you can also invest in a pet drinking fountain.
  • Train the dogs to maintain dryness in the anal region.

Affected Dog Breeds Of Perianal Fistula

German Shepherd, English Setter, Golden Retriever, Middle Age Dogs

Additional Facts For Perianal Fistula In Dogs

  1. Causes:
  • Congenital
  • Allergic skin diseases/ Cell-mediated immunity (T-cell involvement).
  • Conformation-related issues (like limber tail -tucking the tails close down to anuses).
  • Anal Sac Rupture
  • Anal Sac Abscessation
  1. Morbidity:
  • Perianalrefers to the opening of the rectum to the outside of the body, the area immediately surrounding the anus.
  • A fistula is an abnormal passageway or tunnel that forms between organs, body cavities, or the body surface that normally does not connect.
  • The involvement of anal glands in the process of fistulation is not yet confirmed, but there is a clear association with mucous diarrhea of colitis (inflammatory bowel disease).
  • German shepherd dogs are most affected (80%), however, any breed can be affected.
  • The reason proposed to explain why the German shepherd breed is the most affected is it has an increased number of apocrine sweat glands. These sweat glands produce pheromones odorless, oily sweat (it is not stinky unless it is mixed with dirt and bacteria) in the anal area relative to other breeds (watery sweat).
  1. Mortality:

Perianal fistulae is not a fatal disease and death due to this condition is rare.

  1. Diagnosis:
  • Physical Rectal Exam
  • Tissue Biopsy
  1. Prognosis:

Vets may consider providing both medical and surgical treatments for 80% of dogs suffering from perianal fistulas. In most cases, the condition will resolve after lengthy treatment. Up to 20% of cases are unresponsive and require lifelong monitoring and, potentially, lifelong treatment.

When To See A Vet For Perianal Fistula In Dogs?

Contact your vet right away, if you notice any of the following:

  • As the disease progresses, the affected dog will usually lick excessively at its tail and rectal regions, there will be blood in the feces and strain during defecation.
  • Some dogs will appear agitated, gets aggressive if the tail, or hindquarters are touched, and are reluctant to sit, and some may not wag their tail normally.

Food Suggestions For Perianal Fistula In Dogs

  1. A raw diet with little bone content.
  2. Leafy greens such as steamed broccoli.
  3. Add canine formulated prebiotics and/or probiotics to your dog's diet.
  4. Try this great fiber broth recipe:
  • 2 tbsp psyllium husks.
  • 1 Cup of bone broth.

Heat up the bone broth and put it in psyllium husks.

Stir with a spoon until becomes jelly-like (This takes only a few minutes).

Let the mixture settle down and cool for some time.

Feed your dog as required for 1-2 days as a meal replacement.

Don’t overfeed it may cause constipation.


Most pet owners don’t have the habit of checking the area under their dog’s tail unless the dog tends to do something that indicates a problem. Also, only a few clinical signs are manifested initially as the condition may go unnoticed.

Perianal fistulas can be painful and affect the quality of life of dogs and owners terribly. Depending on the treatment, the condition recurs in as many as 80% of dogs. So it’s good to see a board-certified veterinary dermatologist or internist as early as possible.

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