By Dr. Becker
Unlike many humans who tend to sneeze frequently due to allergies, colds, sinus problems, or just an annoying itchy nose, dogs don't typically sneeze very often or for the same reasons.
For example, if your canine companion has an upper respiratory disorder, he's more likely to cough than sneeze, and allergies in dogs are often expressed through the skin. Allergic dogs often have unbearably itchy paws, ears, or skin, and the itch-scratch cycle can result in hot spots or other inflammatory conditions or infections.
Now, this is not to say dogs never sneeze due to allergies or an upper respiratory condition. However, there are other more common causes that should be investigated as well if a dog is sneezing a lot.
Common Causes of Sneezing in Dogs
A sneeze, medically speaking, means "To expel air forcibly from the mouth and nose in an explosive, spasmodic involuntary action resulting chiefly from irritation of the nasal mucous membrane."1
Some of the reasons your dog might sneeze include:
• Foreign bodies
A "foreign body" in your dog's nose means there's something in there that shouldn't be. For example, if your furry family member likes to dig in the dirt or obsessively sniffs the ground, chances are she'll wind up with some soil, grass or the occasional bug up her nose.
This will cause her to sneeze to expel the foreign material. Hunting and sporting dogs who spend a lot of time outdoors running at full speed through natural settings can also wind up with odd things (e.g., twigs or sticks) up their nose.
Sneezing will ensue as the dog's body tries to expel the foreign invader. Sometimes, however, medical intervention is required. Suffice it to say, the list of weird stuff veterinarians have removed from doggy noses is a long one!
Signs of the presence of a foreign object in your dog's nose include sneezing, pawing at the nose, and nosebleeds. You might also notice your pet's breathing is noisier than normal, and there might be a visible bulge or lump on one side of the face or nose.
Foxtails are treacherous little plant awns that are ubiquitous in California, reported in almost every state west of the Mississippi, and have recently spread to the east coast as well.
In late spring and early summer, foxtail plant heads turn brown and dry, and scatter across the landscape. The tiny spikes on the plant heads allow them to burrow into soil, and wildlife also helps spread them around.
The foxtails can eventually make their way into the noses, eyes, ears, mouths, and just about every other opening of a dog's body. They can get deep into your dog's nostril or ear canal or under the skin in no time, and often too fast for you to notice them.
If your dog suddenly starts sneezing uncontrollably, he could have a foxtail in his nose. If you suspect he's been exposed to foxtails or is exhibiting suspicious symptoms, I recommend you consult your veterinarian or an emergency animal clinic as soon as possible.
Whereas bacterial and viral infections of a dog's upper respiratory tract typically cause coughing, an infection caused by the opportunistic Aspergillus fungus causes sneezing.
A nasal Aspergillus infection is thought to develop from direct contact with the fungus through the nose and sinuses, which occurs when a dog is exposed to outdoor dust, hay, or grass clippings. Symptoms in addition to sneezing include pain and bleeding and/or discharge from the nose, and visible swelling.
In addition, an infected tooth or its root can cause your dog to sneeze. In canines, the third upper premolar has roots that are very close to the nasal passages. If this tooth or one close by becomes infected, sneezing and nasal drainage can be the result.
• Nasal tumors
Nasal tumors are fairly common in dogs, especially breeds with longer noses like the Collie. Second- and third-hand tobacco smoke has been identified as a significant cause of nasal cancer in pets. Most types of nasal tumors do not metastasize, but they do spread locally, destroying the structures of the nose.
Sneezing can be a symptom of a nasal tumor, along with chronic nasal discharge. Sadly, dogs with nasal cancer have a poor prognosis.
• Nasal mites (Pneumonyssoides caninum)
Nasal mites are microscopic little bugs that can take up residence in your dog's nose and sinuses. They cause terrible itching in the nose, which triggers fits of sneezing. The mites can also cause nosebleeds and chronic nasal discharge.
Your dog can get a nasal mite infestation by digging in the dirt with her face, or by going nose-to-nose with an infected dog. The mites can be identified by taking a nasal swab and looking at it under a microscope. If there is an infestation, the mites will be visible.
• Household products
The same household chemicals that trigger sneezing in people can also cause dogs to sneeze. Indoor irritants like cologne, cigarette smoke, household cleaners, fiberglass, pesticides, and aerosol deodorants can trigger sneezing in sensitive dogs.
• Brachycephalic breeds
Brachycephalic dogs are breeds with pushed in faces (very short muzzles), including the Boston Terrier, Bulldog, Cavalier King Charles Spaniel, Pekingese and the Pug. The nasal passages in brachys are compressed, which can trigger sneezing spells when there's an upper respiratory infection or exposure to irritants.
• Anticipation or excitement
Interestingly, some dogs, especially little guys, tend to sneeze in anticipation of something exciting about to happen. The "happening" might be receiving a treat, going for a walk, or taking a ride in the car.
When a Sneeze Is Not a Sneeze…
The unsuitably named "reverse sneeze" isn't actually a sneeze at all. The condition does have several other names, but they're tongue twisters, including mechanosensitive aspiration reflex, inspiratory paroxysmal respiration, and pharyngeal gag reflex.
Reverse sneezing is a fairly common respiratory event that happens more often in small breed dogs and brachycephalic breeds. In a regular sneeze, air is pushed out through the nose. In a reverse sneeze, air is pulled rapidly and noisily in through the nose. For some dogs, it's a more or less normal event.
The sound that accompanies reverse sneezing is a sudden, startling noise similar to a honk that makes many dog owners think their pet is either choking or having an asthma attack.
A dog who is reverse sneezing typically stands still with his elbows spread apart, head extended or back, eyes bulging as he makes a loud snorting sound. The strange stance coupled with the strange snorting sound is why many dogs get rushed to the veterinarian or the emergency clinic by their panicked parents.
Episodes of reverse sneezing can last from a few seconds to a minute or two. As soon as it passes, the dog breathes normally once again and behaves as if nothing happened.
If your dog is experiencing repeated sneezing episodes rather than just the occasional sneeze or "sneezing fit," I recommend making an appointment with your veterinarian. This is especially important if there are other symptoms along with the sneezing, such as nasal discharge, bleeding from the nose, or difficulty breathing.