What Is an Oronasal Fistula?
An oronasal fistula is a hole that connects the mouth with the nasal cavity. The bone between the upper tooth roots and the nose is very thin, so when that bone is destroyed, food, water and bacteria can pass from the mouth into the nose. Unlike a cleft palate, which is present from birth, an oronasal fistula is usually acquired later in life.
Most common cause
Advanced periodontal disease around the upper canine teeth. Infection eats away the bone around the root until the tooth socket opens into the nose.
Causes
- Periodontal disease: especially in small breeds and long-nosed breeds such as Dachshunds and Greyhounds
- Tooth extraction: an opening can appear after an upper canine is removed if the gap is not closed properly; see dog tooth extraction
- Trauma: bite wounds, falls, electric cord bites or foreign objects such as sticks
- Tumors: oral or nasal cancers that destroy the bone
- Previous surgery or radiation to the mouth or nose
Signs to Watch For
- Nasal discharge on one side, sometimes with blood or pus; see runny nose in dogs
- Sneezing, especially during or right after eating or drinking; see dog sneezing
- Food or water coming out of the nose
- Bad breath and signs of mouth pain, like chewing on one side
- A visible hole in the gum where a tooth used to be
Diagnosis
Your vet will examine the mouth, usually under anesthesia, and gently probe the gum around the upper teeth. If the probe passes into the nose, or fluid flushed into the pocket comes out of the nostril, a fistula is confirmed. Dental X-rays show how much bone has been lost and whether other teeth are affected.
Treatment
- Surgical closure: the vet cleans the area and closes the opening with a flap of gum and cheek tissue
- Removing diseased teeth: infected roots near the hole are extracted at the same time
- Aftercare: soft food for about two weeks, pain relief, sometimes antibiotics, and no chew toys while the flap heals
- Revision surgery: large or long-standing fistulas sometimes need a second procedure
Prevention
Regular home brushing and professional cleanings are the best protection. See our guide to dog dental care for a simple routine.
Frequently Asked Questions
Will an oronasal fistula heal on its own?
Almost never. The opening tends to stay open and keeps the nose infected, so surgical repair is usually needed.
Is an oronasal fistula an emergency?
It is not usually life threatening, but it causes ongoing pain and infection, so book a vet visit soon.
Can cats get oronasal fistulas?
Yes. Cats can develop them after dental disease, tooth resorption or injury, although they are seen more often in dogs.
If your pet sneezes while eating or has a one-sided nasal discharge, have the mouth checked. Find a veterinary clinic near you for an exam.