Oronasal Fistulas: A Cause of Sneezing and Runny Noses in Pets

Medical articles
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Many pet parents mistakenly attribute chronic sneezing and nasal drip in pets to allergies because they are unaware of a much more serious cause. This issue, an oronasal fistula, receives very little attention but causes many pets misery.

What is an oronasal fistula?

An oronasal fistula is an abnormal opening between the oral and nasal cavities. They are often hidden around teeth that appear normal. Oronasal fistulas allow water, saliva, plaque bacteria, and even small food particles to enter the nasal cavity and cause chronic nasal infections.


While there are uncommon causes for oronasal fistulas forming (such as penetration of foreign objects or aggressive bone-destroying tumors), the majority of oronasal fistulas start out with destruction of the bony tissue between the teeth of upper jaw, or maxilla.


You may think that a hole between the mouth and nasal cavity would be obvious, but it usually isn’t. Common symptoms include chronic sneezing, blood-tinged saliva or nasal discharge, and chronic runny nose (not always bloody). Signs of periodontal disease, such as tartar build-up, bad breath, reddened or swollen gums, and missing teeth, may also be seen. Food particles may even be seen coming out of the nostrils on occasion.

The pet suffering from oronasal fistulas often has a history of improving while on antibiotics but never clearing the infection entirely. The symptoms don’t seem to resolve and many pet parents are left frustrated, having spent much time and expense on medications with no resolution.

Oronasal Fistulas in Cats and Dogs

While cats can certainly develop oronasal fistulas, we see them more often in dogs. In particular, in small breed dogs that are prone to developing severe periodontal disease, such as DachshundsPoodles, and Yorkies, as well as long-nosed breeds such as Greyhounds.


Diagnosing an oronasal fistula requires a close oral examination. Sedation or anesthesia is necessary to safely probe in the mouth as physically exploring the tract is necessary, but dental radiographs may also reveal the fistula.

If a hole is discovered, sterile saline is squirted into the entry in the mouth and will come out through the nose, often bringing debris, old food, and infected material.