Abnormal Passageway Between the Mouth and Nasal Cavity in Dogs

An oronasal fistula is an open passageway between the mouth and nasal cavity. This passageway occurs when a hole opens up near the root of a weakened tooth. Fistulas are often the result of severe gum disease and most commonly affect the upper canines. Although it is possible for the lower teeth to be affected, this is rare.

Water and food can travel from the oral cavity, through the hole, and into the nasal passages, resulting in sneezing, nasal discharge, and chronic rhinitis. The real danger of an oronasal fistula is when food and water make their way into the respiratory tract. This can lead to inflammation and infection of the respiratory tract.

Oronasal fistulas commonly affect small breeds, like Dachshunds. Long-nosed breeds like Greyhounds are also predisposed to developing oronasal fistulas. There are several causes of this condition. With prompt treatment, affected dogs can live a long and healthy life.

Because gum disease is a common cause of this condition, you may notice symptoms of this condition first, including:

• Tartar build-up
• Bad breath
• Swollen gums
• Tooth loss
  

Some dogs may not show any symptoms. However, if you notice any of the following clinical signs, consult your vet as soon as possible.

• Inflammation or infection of the nasal cavity
• Irritation of the respiratory tract
  
• Excessive sneezing
• Chronic runny nose
• Bloody saliva or mucus
  

The main cause of oronasal fistulas is severe periodontal disease. Untreated gum disease weakens the bony tissue surrounding the teeth, which can cause oronasal fistulas. Prompt treatment is imperative to prevent bone loss and infection.

Other, less common causes of oronasal fistulas include:

• Complications of tooth extraction
  
• Foreign bodies penetrating the mouth or jaw
  
• Cancer
• Cleft palate
  

As we mentioned earlier in this article, some breeds are more susceptible to developing oronasal fistulas. These include:

• Dachshunds 
• Poodles
• Yorkshire Terriers
• Greyhounds
• Maltese

While this condition is more common in these breeds, it can affect any breed.

If you suspect your dog has an oronasal fistula, a vet visit will be necessary to confirm the diagnosis. Fistulas are difficult to see with the naked eye. Your dog may need to undergo sedation or anesthesia so your vet can fully examine their dental health. X-rays of the jaw and skull may also be required. The vet will use a saline solution to flush out any contaminants like food particles from the passageway.

Oral surgery is the only treatment option for this condition. Dogs experiencing chronic respiratory infections will require a course of antibiotics before the surgery.

The tooth next to the fistula will be removed, along with all of the decayed gum tissue and weakened bony tissue. Once everything is removed, the veterinarian will source a piece of healthy tissue from the gum and suture it over the fistula to close it.

If a fistula has not yet formed, bone grafts and the regeneration of tissue are options to prevent this condition. This procedure, however, is not usually recommended as it does not have a high success rate and is extremely costly to the client. 

The veterinary surgeon will give you instructions on how to care for your dog after the operation. You'll need to prevent your dog from chewing on anything hard — that includes their favorite chew toys and dry kibble.

The prognosis for treatment is generally good. Treating the condition as early as possible is key to ensuring the best possible prognosis.

The good news is, periodontal disease is preventable. Brushing your dog's teeth regularly will go a long way toward preventing gum disease. Dental chews and water additives also remove plaque from your dog's teeth.

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