Why Does My Dog’s Nose Run? Common Causes & When to Call a Vet

Having a runny nose is a pretty common occurrence in dogs because they tend to explore the world around them with their sniffer, getting a lot of dirt, dust, and other potential allergens in their nasal passages. However, if that runny nose comes with discolored discharge or other troubling symptoms, like a high fever, then a visit to the veterinarian is in order to have him treated for something that could be much worse.

Just like us, our dogs can easily catch a cold or flu when visiting a friend's dog, during a trip to the dog park or doggie day care, or when visiting the groomer. A common cause of a dog's runny nose is canine influenza. In addition to a runny nose, your dog may appear lethargic or have a fever, and he may not want to eat. There are no treatments for the viruses that cause canine influenza other than keeping your dog as comfortable as possible while he recovers.

Another cause of a runny nose in dogs is kennel cough. This is a bacterial or viral-based infection that can also cause intense dry coughing and could lead to pneumonia. Treatment for these infections can include antibiotics. Fortunately, a vaccine can help prevent kennel cough.

Some very serious and potentially fatal diseases, like canine distemper, can also cause a runny nose in dogs. Usually, this will come with more serious symptoms, like diarrhea, lethargy, a lack of appetite, and a fever. Although there is no cure, a vaccine can prevent distemper in dogs.

Something stuck in a dog's nose

While your dog is sniffing her way through the day, she may encounter something dangerous, like a foxtail, while out in the wilderness. These sharply barbed grass seed pods are usually found in tall grasses in overgrown fields. If your dog inhales one of these grass awns, it can cause a runny nose, sneezing, and trouble breathing.

If your dog has gotten a foxtail or some other foreign object in her nose, your vet will need to examine your dog to see about surgically removing the object before it leads to further damage or pneumonia.

Nasal tumors or polyps causing discharge

One of the more serious causes of any type of nasal discharge in dogs is an abnormal growth within the nasal passages. These growths include nasal tumors or polyps, which can be cancerous. Your veterinarian will need to examine your dog's nose by performing a rhinoscopy with a camera under anesthesia. The doctor may also give your dog a CT scan. Treatment for these conditions could include surgery or radiation therapy.

Other causes of a canine runny nose

Your dog's nose may be running due to his breed. That's because flat-faced brachycephalic breeds, like the French bulldog, Pekingese, pug, Shih Tzu, and Boston terrier, are prone to developing runny noses. Sometimes, dogs simply get excited or become overheated and may sweat through their nose. This usually resolves itself quickly after your dog calms down or cools off. Although seemingly unrelated, dental problems can actually cause runny noses in dogs. That's because the teeth are located very close to the nasal passages, and a dental infection could trigger your dog's runny nose.