What Is an Oronasal Fistula in Dogs?
An oronasal fistula is an abnormal opening that forms a passageway between a dog‘s oral and nasal cavities. In most cases, it occurs as a complication of losing a tooth or having one extracted, especially the long canine teeth. The hole left behind in the gums fails to heal properly, leading to a permanent fistula or tunnel into the nose.
Although it may start small, an oronasal fistula will not close on its own. It can allow food particles, water, saliva and bacteria from the mouth to enter the nasal passages, quickly leading to irritation and infection. Treatment by a veterinarian is necessary to repair the fistula and restore healthy anatomy.
Why Do Oronasal Fistulas Form?
You may not realize how closely interconnected your dog‘s mouth and nose are. If you picture the skull beneath all the overlying tissues, you‘d see that the upper teeth, especially the long canine teeth, have roots that extend very near the nasal cavity. A bAffected vs. Normal Dog Jaws.jpg" />
Normal anatomy has a solid bony floor separating the oral and nasal cavities. But when a tooth is lost due to advanced periodontal disease or trauma, the only barrier remaining may be a thin membrane. Oronasal fistulas develop when even that membrane breaks down, allowing free flow of material between mouth and nose.
Dental disease is extremely common in dogs, with over 80% showing signs of periodontitis by 3 years of age according to veterinary dental experts. When tartar builds up and gum inflammation progresses, the ligaments anchoring a tooth in its socket deteriorate. The tooth becomes loose and may fall out on its own or require surgical extraction.
Whenever a tooth is removed, the extraction site should be sutured closed by the vet to promote rapid healing. But sometimes the gums fail to seal over the opening due to factors like:
- Improper suturing technique that doesn‘t adequately cover the hole
- Infection of the extraction site
- Excessive chewing/self-trauma that disrupts the healing tissues
- Underlying health issues that slow healing, like diabetes or autoimmune disease
A dog that loses a tooth on their own without veterinary care is at very high risk of developing an oronasal fistula, since no sutures are placed to close the defect. Fistulas can also arise due to injury, benign or malignant oral tumors, and rarely congenital defects.
Signs of an Oronasal Fistula
The most obvious indicator of an oronasal fistula is a visible opening in the gums where a tooth used to be. Often the hole is circular and about the diameter of a pencil eraser, although the size can vary. In some cases, the fistula may not be readily apparent, especially if hidden by inflammation, and is only diagnosed with dental x-rays that reveal the abnormal connection.
Other symptoms a dog with an oronasal fistula may display include:
- Chronic nasal discharge, often unilateral
- Sneezing, snorting, reverse sneezing
- Halitosis (bad breath)
- Open mouth breathing
- Appetite change, especially preference for soft foods
- Bloody or mucoid discharge from the fistula opening
- Pawing at the face/nose
Since an oronasal fistula allows material to move from the mouth into the nose, dogs often experience recurrent rhinitis and sinusitis. Keeping the nasal passages healthy and free of infection is impossible until the underlying fistula is repaired.
Treating an Oronasal Fistula
The only way to correct an oronasal fistula is through surgical intervention under general anesthesia. The goals of surgery are to remove damaged tissue, reestablish a barrier between oral and nasal cavities, and close the gingival defect.
First, dental x-rays are taken to define the extent of the fistula and assess whether any tooth roots remain that could cause continued inflammation. The fistula is then debrided of any debris or unhealthy tissue and thoroughly flushed.
To rebuild a solid floor over the bony defect, a flap of mucosa (oral lining) is dissected from a neighboring area and sutured into place over the fistula. This flap is crucial to preventing the recurrence of an oronasal communication. The gums are closed with absorbable sutures to fully cover the repair.
While the dog is under anesthesia, a complete oral examination and dental cleaning is typically performed to address any periodontal disease. This helps optimize oral health and reduce the risk of additional tooth loss in the future.
Recovery and Aftercare
Postoperative care following oronasal fistula repair is critical to achieving a good outcome. For the first two weeks, dogs should eat only soft food and avoid all chews and toys to protect the surgical site. Antibiotics and pain medications are routinely prescribed.
Recheck examinations are important to monitor healing of the repair. The mucogingival flap must establish a blood supply from its new bed to survive and seal off the fistula permanently. Most dogs recover fully and have an excellent long-term prognosis.
Once the gums are healed, a home dental care routine can begin. Daily tooth brushing is ideal, using a dog-specific enzymatic toothpaste. Owners should schedule professional teeth cleanings at the vet every 6-12 months to keep periodontal disease at bay and catch any problems early.
Cost of Oronasal Fistula Repair
Because it is a specialized oral surgery requiring general anesthesia, the cost to repair an oronasal fistula in dogs typically ranges from $1200-1800. Costs may be higher if tooth extractions are necessary or for complex fistulas that have been present a long time. Dental x-rays and medications add to the total bill.
While it can feel like a big expense, surgical treatment is important for a dog‘s comfort and quality of life. Delaying allows the fistula to enlarge and become tougher to repair. Chronic nasal infections also take a toll.
Many veterinary practices offer payment plans or accept Care Credit. Pet insurance plans that include dental procedures can help offset the cost. The best way to avoid needing oronasal fistula surgery is preventing dental disease through home care and regular vet cleanings.
When to See the Vet
If you notice a hole in your dog‘s gums, especially after a tooth falls out or is extracted, make an appointment with your veterinarian right away. Quick intervention gives the best chance of successful treatment.
You should also see the vet if your dog has foul odor from the nose or mouth, nasal discharge, nosebleeds, or any other signs of dental problems. Catching oral disease early can keep your dog‘s teeth firmly in place and prevent complications like oronasal fistulas from developing.
With over a decade in clinical practice, I‘ve treated many dogs with oronasal fistulas. One particularly memorable case was a Labrador retriever named Max who lost a canine tooth and subsequently developed a large fistula.
Max‘s owner noted chronic bad breath and nasal drainage but didn‘t realize the seriousness until Max started having nose bleeds. On examination, I found a one-centimeter wide defect extending from his upper gums into his left nasal passage.
We scheduled surgery right away. Under anesthesia, I debrided the fistula and created a gingival flap to close the opening. Max recovered smoothly and his nose remained clear and healthy from then on. His owner committed to daily tooth brushing to safeguard Max‘s oral health.
The take-home message is that any time a dog loses a tooth, whether on its own or by veterinary extraction, you need to monitor the site closely. Oronasal fistulas should be treated promptly to restore proper anatomy and prevent chronic nasal disease. With attentive at-home care and regular professional evaluations, you can keep your dog smiling for years to come.
