Why is my dog sneezing?

What happens when a dog sneezes?

Sneezing is the body’s normal reaction to a possible irritant or allergen inside the nasal passages. A dog’s nasal cavity is lined by rows of small hair-like projections called cilia. These help trap any allergens or irritants that a dog may accidentally inhale and prevent them from traveling further down the respiratory tract.

The nasal passages are also highly vascularized and can mount an inflammatory or immune response to any possible pathogen trapped between its ciliated mucosal lining. When an allergen or environmental irritant enters the nasal cavity, it is trapped by the cilia of the nasal mucosa. The lining will then produce serous or mucoid discharge and, with the help of the movement of cilia, will facilitate the removal of these irritants.

Sneezing occurs when the nasal lining transmits signals to the brain and mounts an immune response against the allergen or irritant, causing contraction of the nasal cavity lining and surrounding tissues. The inflammatory response results in sneezing, a forceful elimination of the irritant from the nasal cavity.

Common Causes of Sneezing in Dogs

As mentioned, sneezing in dogs usually happens as a reaction to an inhaled irritant or allergen. Listed below are some of the most commonly reported causes of sneezing in dogs.

Allergic Reactions

Dogs have a very sensitive sense of smell and any strong scents or environmental airborne molecules can trigger an allergic reaction. While most allergy cases in dogs manifest as a skin problem, inhaled allergens can cause an inflammatory response along the lining of the nasal passages (termed rhinitis) and cause sneezing in dogs.

The severity, frequency, and duration of the sneezing are dependent on the type of allergen inhaled and how long the animal was exposed to it. Most allergic rhinitis in dogs can cause mild, transient sneezing but there are cases where excessive and prolonged sneezing is seen. Antihistamines and corticosteroids, especially those that are inhaled, are often effective in controlling sneezing due to allergic reactions.

Behavioral Sneezing

It has been observed that dogs sometimes sneeze with no apparent medical cause. They usually exhibit this peculiar behavior during playtime, which is often interpreted as a sign of happiness. Other dog owners have observed that dogs occasionally sneeze when trying to get their attention. Dogs will often look at their owners after sneezing to see if they were able to get the human’s attention.

Respiratory Tract Infection

Most respiratory infections in dogs affect the lower respiratory tract and cause persistent coughing as the primary clinical sign. But several bacterial and viral infections can affect the upper respiratory tract, including the nasal passages. Infections can cause frequent sneezing, along with profuse nasal discharges, which usually persist unless the underlying infection is treated or controlled. Common respiratory infections that may cause sneezing include canine influenza and canine infectious respiratory disease complex (CIRDC).

Foreign Material in the Nose or Nasal Passages

Dogs use their nose to gather information about their environment. When walking outside, they spend most of their time sniffing around different places and objects. This behavior makes them at high risk of inhaling foreign objects from the environment. Reports of grass blades, foxtails, food particles, and hair strands lodged in a dog’s nasal cavity are common in veterinary facilities.

Having a foreign body stuck inside the nasal cavity causes frequent and continuous sneezing. For dogs, sneezing is their way of removing anything that could have gotten stuck inside their nasal passages. The sneezing usually persists until the foreign material is successfully removed, either on its own or with veterinary intervention.

Nasal Mites

Dogs can contract microscopic parasites called nasal mites. These parasites invade the epithelium of the nasal cavity and feed on the blood vessels in the highly vascularized lining of the nasal passages. The presence of nasal mites results in excessive sneezing, often with mucoid or bloody discharge due to severe inflammation of the nasal passages.

Nasal mites are diagnosed through nasal endoscopy (nasal scoping) or nasal flushing. The presence of mites can be confirmed through microscopic exam of samples obtained from the nasal passages. Common anti-parasitic treatments are often effective in eliminating nasal mites in an infected dog.

Nasal Tumors

In older dogs, nasal tumors are usually considered when assessing frequent sneezing. Many nasal tumors seen in dogs are cancerous or malignant, and only around 20% are found to be benign. Fortunately, nasal cancer is rare in dogs, accounting for only 1-2% of all reported cancer cases.

Malignant or not, the presence of nasal tumors in dogs can result in continuous and persistent sneezing, along with nasal discharge that can be mucoid or bloody depending on the type of tumor. Dogs with nasal tumors will often have systemic signs of illness like weakness and decreased appetite. If the tumor is left undiagnosed and untreated, the disease can progress and cause additional symptoms such as snoring, breathing difficulties, and exercise intolerance.

Diagnosis of nasal tumors can be done through imaging procedures. While radiographs (x-rays) can detect the presence of nasal tumors, other methods such as MRI (magnetic resonance imaging) or CT (computed tomography) scan of the head can give a more complete and detailed picture of the size and extent of the tumor.

Because of the location, surgical removal of nasal tumors is not usually recommended. Treatment for such cases involves radiation or chemotherapy, depending on the type of nasal tumor the dog has.

Read more:

Bloody Noses in Dogs and Cats

Reverse Sneezing in Dogs

Sneezing in Cats and Kittens

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