Sneezing and nasal discharge in a dog or cat: when the teeth are to blame
Owners don't usually connect sneezing and a runny nose with the teeth, but they should: the roots of the upper canines and the upper back teeth are separated from the nasal cavity by only a thin layer of bone. When periodontal disease, an abscess or an injury destroys this partition, bacteria, fluid and food particles get into the nose. There are many causes of sneezing, and not all of them are dental, so the first step is to find out where the problem comes from.
Important note for owners
It is a warning sign when the discharge comes from one nostril, the sneezing starts during or right after eating or drinking, and the breath smells bad. In cats, sneezing is frequently caused by upper respiratory infections, but the teeth are worth checking too.
Most common possible causes
- —Oronasal fistula due to periodontal disease. Periodontal disease destroys the bone on the palatal side of an upper canine, and an opening forms between the mouth and the nose. Small breeds, Dachshunds among them, are predisposed; the canine may still look firm.
- —An extraction site that wasn't closed. If the bony partition was already destroyed and the socket of an upper tooth wasn't closed with a gum flap after extraction, a communication with the nose can remain.
- —Root abscess of an upper tooth. Infection at the root tip — after a tooth fracture or due to deep periodontal disease — can break through into the nasal cavity and cause discharge on one side.
- —Injury. A blow, a fall or a bite can damage the palate, the teeth and the bone between the mouth and the nose.
- —Cleft palate in puppies and kittens. This is a congenital defect of the palate: milk or food comes out of the nose during nursing or eating.
- —Causes outside the mouth. Upper respiratory infections (especially in cats), foreign bodies such as grass awns, nasal tumours, fungal infections or allergies. These need other tests and possibly a different specialist.
When not to postpone an exam
- ✓Discharge from one nostril, especially with food particles or traces of blood
- ✓Sneezing during or right after eating or drinking
- ✓Milk or food coming out of the nose in a puppy or kitten
- ✓Bad breath, tartar, loose upper teeth or nasal symptoms after a tooth extraction
- ✓Sudden violent sneezing and pawing at the nose after a walk — a grass awn may be stuck in the nose
- ✓A deformity of the face or nose, or a nosebleed in an older pet
Urgent help needed
- ✓Active bleeding that will not stop
- ✓Bleeding from both nostrils, or bruising on the skin or gums — a possible blood-clotting disorder (for example, rodenticide poisoning)
- ✓Difficulty breathing
- ✓Rapidly increasing swelling of the face, cheek or under the eye
- ✓A newborn with milk coming from the nose is gaining weight poorly, coughing or struggling to breathe
- ✓Complete refusal of food and water
What you can do at home
- ✓Note which nostril the discharge comes from, its colour and when the sneezing happens — while eating, drinking or unrelated to either.
- ✓Record a short video of a sneezing episode and photograph the discharge.
- ✓Lift the lip and photograph the upper canines and back teeth from the side. You can send the photos for an online consultation on Telegram, but they don't replace an examination.
- ✓Gently wipe the nose with a soft damp cloth.
What not to do at home
- —Don't use human nasal drops or sprays — some of them are toxic to dogs and cats
- —Don't give leftover antibiotics from previous treatment: they won't close the opening between the mouth and nose
- —Don't give human painkillers — many of them are toxic to pets
- —Don't flush the nose or “check” an opening in the mouth with instruments
- —Don't wait for weeks for the “cold” to pass, especially if the discharge is one-sided
What diagnostics may be needed
- ✓Consultation: the mouth, nose, breathing and how the symptoms relate to eating
- ✓Probing of the palatal side of the upper canines under anaesthesia: with a fistula, the probe passes into the nasal cavity
- ✓Full-mouth dental radiography as part of COHAT
- ✓If the cause is not dental, a CT scan, rhinoscopy or a consultation with your regular vet may be needed
When the canine is still in place, a fistula is usually invisible both in photos and during an examination without anaesthesia: it hides in a deep periodontal pocket. It is found by probing under anaesthesia, and the roots and bone are assessed on dental X-rays — only then do I make a treatment plan.
Unfamiliar term in the diagnosis?If the report mentions TR, FCGS, pulpitis or a periodontal stage, the glossary explains each term briefly.GlossaryHow treatment may proceed
- ✓Extraction of the affected tooth and closure of the fistula with a tension-free gum flap
- ✓Treatment of periodontal disease in the other teeth as part of COHAT
- ✓Surgical closure of a chronic fistula or cleft palate; the plan depends on the size of the defect and the state of the tissues
- ✓Pain relief and, if needed, antibiotics — only as prescribed by a vet after examination
- ✓Non-dental causes are treated by the relevant specialist
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Frequently asked questions
Yes. The roots of the upper teeth lie next to the nasal cavity, so periodontal disease or a root abscess can cause sneezing and nasal discharge.
An antibiotic prescribed by a vet can reduce inflammation for a while, but it doesn't close the opening between the mouth and nose or treat the tooth. That is why symptoms frequently return after the course until the cause is dealt with.
Usually not: when the canine is still in place, the opening hides in a pocket on the palatal side. After an extraction, an opening in the socket is sometimes visible. Don't check it with instruments — take a photo and show it to the vet instead.
It could, although in cats sneezing is frequently linked to upper respiratory infections. If the discharge is one-sided, started after an extraction, or there is bad breath and loose teeth, the mouth should be examined too.
Food and bacteria from the mouth keep getting into the nose and maintain chronic inflammation. The longer the communication exists, the more complicated closing it may become.
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