Sneezing (and reverse sneezing) is a reflexive spasm of the throat and soft palette. It is triggered by an irritation to the roof of the back of the throat known as the nasopharynx. Irritation to this area can be caused by a variety of things.
Some dogs will have a reverse sneezing episode triggered from getting excited, or if they pull on their collar around their throat. Environmental irritants such as pollens, perfumes, or sudden change in air temperature can all trigger reverse sneezing.
In most cases, sneezing and reverse sneezing is nothing to get too worried about, but in some situations, persistent sneezing (and reverse sneezing) can be a sign that there is something more serious going on. These include:
Like humans, dogs can also have allergies which can lead to sneezing. If you notice a seasonal change in your dog’s sneezing habits, it could very well be from environmental allergies to certain pollens or plants. Your veterinarian will be able to run tests to see if your dog has environmental allergies.
Dogs can develop dental disease that, if severe, can lead to an oronasal fistula where an abnormal connection develops between the oral cavity and the nasal passageways. If this is the case your veterinarian will likely have to remove the diseased problem tooth or teeth. Your dog will feel much better afterwards!
Pro Tip: If your dog will tolerate you handling their mouth, you can examine their mouth for bad breath and ‘rotting’ teeth. These are signs of severe dental disease frequently associated with oronasal fistulas.
Nasal Infections (Aspergillosis)
Aspergillus fungus is spread by the inhalation of mold spores found in the environment on dead leaves, compost piles or other dying vegetation (you normally encounter it on bread that’s gone bad). Normally these situations will be self-limiting and clear up on their own, but immunocompromised dogs may develop an infection, with symptoms such as sneezing, nasal discharge, bloody discharge, facial swelling, fever and weight loss. Your dog will need to see a veterinarian and receive appropriate testing and treatment.
Foreign Object in the Respiratory Tract
Dogs love to sniff their way along the ground and can end up with something stuck in their nasal passage. It could be a grass seed, a leaf or a stick. Your dog will likely paw at their nose, and may be able to sneeze it out but, if not, your veterinarian may need to remove it. It is best not to try to remove anything yourself that is up inside the nasal cavity as you may accidentally push it further inside. Veterinarians have specialized tools made just for this purpose.
Pro Tip: Do not try to remove a foreign object lodged within the nasal cavity, as you may accidentally push it further in.
Nasal Polyp or Tumor
Unfortunately, in some rare cases ongoing sneezing can be a symptom of something more serious, like a nasal tumor or cancer. Nasal tumors can be associated with other symptoms such as difficulty breathing through the nose, bloody nasal discharge and noisy breathing, and often asymmetry or bulging on one side of the muzzle. If you see any of these symptoms you should book an appointment with your veterinarian.
Although it is rare, sneezing can also be caused by small mites that live inside your dog’s nasal passages. They can cause bleeding and nasal discharge and are very bothersome to your dog. They are spread nose to nose between dogs and are highly contagious. Your veterinarian can prescribe medication for your dog to get rid of these little stowaways.
Pro Tip: If you suspect your dog has a contagious condition, isolate them from other dogs to prevent further spreading.
Though uncommon, dogs can get the flu (much less frequently than humans). Unlike humans, sneezing is not a common influenza symptom. An infected dog will most likely have a persistent cough, and may also have other signs such as sneezing, nasal and ocular discharge, lethargy, and anorexia. It is important to isolate your dog from other dogs if you suspect canine influenza, as it is highly contagious. Be sure to let your veterinarian know before arriving at the clinic so they can also prepare ahead of time!