Runny noses in dogs are not uncommon and causes can range from something as simple as allergies to the sign of a more serious problem, including an obstruction or even cancer.
Dogs with short noses, known as the brachycephalic breeds, such as Pugs, Boston Terriers and Bulldogs, are much more likely than other breeds to be susceptible to respiratory problems and a runny nose. An occasional clear discharge with no other signs is likely nothing to worry about, but if your dog starts pawing at his nose, and begins sneezing, coughing or having difficulty breathing, it’s time for a consultation with your veterinarian.
Besides nasal discharge that is common in the brachycephalic breeds, other causes include allergies, infections both viral, bacterial or fungal, a foreign body stuck in the nasal passages, a toxic reaction to a chemical or environmental irritant, a bleeding disorder, trauma with injury to the area and cancer. Nausea in a dog will often be accompanied by nasal discharge as well.
And look out if your dog’s nasal discharge is only on one side. This is a clear indication that you need to see your vet.
If the nasal discharge is clear and isn’t accompanied by any other signs or symptoms, you can likely safely just watch your dog to make sure he doesn’t develop any other problems. But if the discharge lasts more than a week, or the discharge turns green, bloody, thick or crusty or if your dog has a decreased appetite, lethargy, begins to cough or sneeze or have problems breathing, you will want to get him to the vet right away.
Of course the treatment your vet advises will depend on the diagnosis. If the cause is an allergy or your vet suspects a mild viral illness, no treatment may be indicated. But if a more serious infection such as bronchitis or pneumonia is diagnosed, treatment may require antibiotics and medications to suppress his cough. If the infection is severe enough, your dog may require a hospital stay and oxygen.
Foreign bodies can require x-rays or even a CT scan. If a tumor or polyp is discovered surgery may be necessary.