Diagnosing a Dog With Runny Nose Symptoms

Dog runny nose symptoms could have a number of causes. They might be a sign of infection, allergies or dental disease. Here's some more information about the causes of runny nose symptoms in dogs.


One of the most common causes of increased nasal discharge in dogs is bacterial or fungal infection. Your veterinarian will need to take a sample of your dog's mucus and perform a culture. Bacterial infections are treated with antibiotics. Some fungal infections will clear up on their own but some will need to be treated with antifungals.


Dog allergies can cause coughing, wheezing and runny nose. Allergies occur when your dog's immune system overreacts to a non-pathogenic agent. Allergic sensitivities can develop at any time during a dog's life, so don't think they can't make your dog sick just because he's never had them before.

Dog allergies may be seasonal; if so, they'll occur for two or three months during the spring or fall, then symptoms will resolve themselves. Dogs can also be allergic things in their environments, including cleaning products, dust and mold. Allergies can be treated with medication and by removing allergens from the environment.

Dental Disease

Dental diseases, including periodontitis, gingivitis and abscessed teeth, can make your dog very sick. These bacterial infections can spread to the nasal cavities, causing your dog's nose to run. Your vet can diagnose dental disease by examining your dog's mouth. Treatment may involve tooth cleaning or removal of teeth, performed under anesthesia.

Nasal Mites

Nasal mites are a common parasite that infest the sinus passages of domestic and wild dogs; they are also found in the silver fox. Most dogs with nasal mites won't display any symptoms. Others, however, may develop symptoms including sneezing, nose bleeds, and chronic nasal discharge.

If your dog's runny nose is chronic, he may be suffering from a severe infestation of nasal mites. This is especially the case if your dog has recently been housed in a kennel or shelter, as nasal mites are common in these facilities. However, nasal mites are easily treated with an oral dose of the heartworm drug, ivermectin.

Foreign Objects Lodged in the Nasal Passages

If your dog has a runny nose and isn't sick, he might have something lodged in his nasal passages. Dogs often sniff small objects up their noses; he could have inhaled a blade of grass or a seed. Often, your dog will sneeze out the object on his own; if health symptoms persist, your vet can removed the foreign object.

Nasal Cancer

Probably the most serious cause of upper respiratory symptoms in dogs is nose cancer, or nasal adenocarcinoma. Blood in your dog's snot may be a sign of nasal cancer. This type of cancer grows slowly and is very invasive. Nasal tumors don't respond well to chemotherapy or anti-cancer drugs, and surgery to remove them can be difficult due to the complex structure of the sinus passages.

Symptoms of nasal cancer in dogs include:

  • Excessive sneezing
  • Tears
  • Bad breath
  • Prolonged loss of appetite
  • Facial deformity
  • Bulging eyes
  • Seizures

Radiation therapy may be of some use to dogs who remain in the early stages of the disease.