Perianal Fistula Resection in Dogs

Perianal fistula resection refers to a procedure that resects, or removes, perianal fistulas from your dog. Perianal fistulas are growths, lesions, tumors, or other inappropriate tissues that occur in your dog’s anal region. These fistulas can impact or block your dog’s anal glands, causing pain, straining to defecate, and infection. Perianal fistula resection is often used when other procedures to reduce or eliminate the fistulas have not proven effective. Before resection, your vet may prescribe medication, dietary changes or supportive non-medical monitoring. Given the potential for complications from any surgical procedure, unless your dog is in extreme pain or suffering from a secondary condition, such as infection, as a result of the fistulas, perianal fistula resection will usually be a last resort in treatment. 

Before undergoing a perianal fistula resection your vet will prepare the area for surgery. This will involve clipping your dog’s hair around their anus and flushing out the area with a potent cleaning solution. Often time this solution will be medicated to sterilize the area as much as possible prior to surgery.

During perianal fistula resection your dog will need to be anesthetized. To ensure your dog is healthy enough for anesthesia, a pre-surgical blood panel will be ordered. This will help your vet confirm your dog is not suffering from any underlying conditions that may complicate the surgery or cause unnecessary risk.

The removal of the perianal fistula will require a veterinary surgeon who is skilled at working with the numerous small blood vessels that make up your dog’s anal area. The will work slowly and meticulously to remove the fistulas and tie off blood flow that may have developed in the area. Your vet will be careful to remove all fistula material as remaining tissue may grow back causing the condition to recur. Your vet may also follow up the resection procedure by freezing the tissue via cryotherapy. 

Most cases of perianal fistulas will resolve after surgical removal via resection. In up to 20% of cases, fistulas may redevelop throughout your dog’s lifetime, creating the need for intermittent treatment. The effectiveness of perianal fistula resection will often depend on the veterinarian’s skill and their ability to eliminate as much of the tissue as possible to prevent regrowth. 

Alternative procedures often involve supportive measures such as regular flushing of your dog’s anal glands or treatment with steroidal medications that are designed to decrease swelling, inflammation, and tissue size. Cyclosporine and ketoconazole are two medications that are prescribed to treat perianal fistulas and are administered for up to 20 weeks. In some dogs, these alternative treatments will not be enough to eliminate the condition and surgery will be needed to provide relief.

Your dog will begin to see immediate relief after perianal fistula resection. The elimination of the unnatural tissue will allow your dog to defecate more freely and without strain. As with any surgery, your dog should be kept calm and quiet after surgery for a period of up to a week. Your dog may also need to wear a cone or other mobility limiting device to prevent them from licking the wound area or otherwise opening up the incision.

Follow-up may be needed to remove stitches if dissolvable stitches were not used during surgery. Your veterinarian will also prescribe antibiotics to help prevent infection. If the incision site heals well and does not reopen, you should expect your dog to make a full recovery within one to two weeks.

The cost of perianal fistula resection in your dog will range from $500 to $1,200, with several factors affecting the exact price. Anesthesia costs for surgery will vary depending on the size of your dog. If there are excessive fistulas or both anal sacs are affected, this could also increase the cost. This price reflects pre-surgical procedures, the surgery itself as well as medications needed post-surgery to prevent infection.

If surgery is effective, perianal fistula resection will have long-term benefits for your dog. They will be able to defecate properly, will no longer be in pain and will not run the risk of infection from impacted anal glands. As with any surgery, there are some risks from anesthesia or unforeseen complications, but generally most dogs recover well. If the fistula is not able to be fully excised, the growths may return, creating the need for multiple treatments over the course of your dog’s life. Additionally, even if a fistula is removed others may regrow in its place.

There is no current method known for preventing perianal fistulas in your dog. Veterinarians and canine nutritionists recommend giving your dog a balanced diet that is low in carbohydrates such as rice, corn, or potato. Immune support with probiotics has also proven helpful in reducing fistula growth and regrowth in some cases. There is also some evidence that canine fistulas may be linked to autoimmune conditions. Finally, there is also a theory that poor circulation around the anus could cause fistulas to form. You should keep your dog’s fur in this area well-groomed and clipped when possible.