When Sneezing Matters
Occasional sneezing is normal, particularly after sniffing grass, dust, or pollen. Dogs also have a “play sneeze,” which is a short, voluntary snort used during social interactions to signal that rough play is friendly. Neither requires medical attention.
Sneezing becomes concerning when it is: persistent (many sneezes in a row, repeated throughout the day), violent (paroxysmal sneezing that seems uncontrollable), one-sided (one nostril affected more than the other), accompanied by nasal discharge (especially bloody, yellow, or green), or accompanied by pawing at the nose, facial swelling, or epistaxis (nosebleed).
Key diagnostic clue: unilateral (one-sided) nasal discharge suggests a localized cause like a foreign body, tooth root abscess, or nasal tumor. Bilateral (both nostrils) discharge suggests infection, allergies, or systemic disease.
Possible Causes Ranked by Likelihood
Common Causes
Environmental irritants. Dust, pollen, perfumes, cleaning products, cigarette smoke, and aerosolized chemicals can trigger sneezing. This is usually transient and resolves when the irritant is removed.
Nasal foreign body. Grass awns (foxtails), small sticks, blades of grass, and other plant material can be inhaled into the nasal cavity during vigorous sniffing. Produces sudden-onset violent, paroxysmal sneezing, often one-sided. The dog may paw at its nose and have unilateral nasal discharge. Foxtails are a particular hazard in western US states. This is the most common cause of acute, violent sneezing that does not resolve within a day.
Upper respiratory infection. Viral (canine parainfluenza, adenovirus) or bacterial infections produce bilateral nasal discharge, sneezing, and possibly coughing. Similar presentation to kennel cough but with more nasal involvement. Most cases are self-limiting within 7-14 days.
Reverse sneezing (pharyngeal gag reflex). Not truly sneezing but often confused with it. A spasmodic episode where the dog rapidly inhales through the nose with a characteristic “honking” or “snorting” sound. Caused by irritation of the nasopharynx. Very common in small and brachycephalic breeds. Episodes are alarming to owners but are harmless and self-limiting.
Moderately Common
Dental disease. Upper tooth root abscesses (particularly the upper premolars and molars) can erode through the thin bone separating the tooth roots from the nasal cavity, creating an oronasal fistula. This produces chronic unilateral nasal discharge and sneezing. The connection between dental and nasal disease is often missed. See the dental disease condition page.
Nasal mites (Pneumonyssoides caninum). Microscopic mites that colonize the nasal passages. Produce chronic sneezing, nasal discharge, reverse sneezing, and head shaking. Diagnosed by nasal flush or endoscopy. Treated with antiparasitic medications.
Fungal infection (nasal aspergillosis). Aspergillus fungus can colonize the nasal cavity, destroying the turbinate bones. Produces chronic, often unilateral, mucopurulent or bloody nasal discharge with sneezing and visible depigmentation or ulceration of the nostril. Golden Retrievers, German Shepherds, and other dolichocephalic (long-nosed) breeds are predisposed.
Less Common but Serious
Nasal tumor. Adenocarcinoma, squamous cell carcinoma, lymphoma, and other tumors can develop in the nasal cavity. Typically affects dogs over 8-10 years. Produces progressive unilateral nasal discharge (often bloody), sneezing, facial deformity, and sometimes neurological signs if the tumor extends into the brain. Long-nosed breeds (Collies, German Shepherds, Golden Retrievers) have higher rates.
Cleft palate. A congenital defect that connects the oral and nasal cavities. Affected puppies sneeze during nursing and have nasal discharge of milk.
Nasal polyps. Benign growths in the nasal passages that cause obstruction, sneezing, and nasal discharge. Less common in dogs than in cats.
Severity Scale
Normal (No Concern)
- Occasional sneezing after sniffing grass, flowers, or dusty areas
- Play sneezing during social interactions
- Brief reverse sneezing episodes in small breeds
Call Your Vet (Within Days)
- Sneezing persisting more than 2-3 days
- Nasal discharge (especially if colored, thick, or bloody)
- Sneezing affecting one nostril more than the other
- Chronic sneezing with progressive worsening over weeks
- Pawing at the nose or visible discomfort
Emergency (Go Now)
- Sudden, violent, uncontrollable sneezing (foreign body)
- Significant nosebleed (epistaxis) that does not stop
- Sneezing with facial swelling or deformity
- Sneezing with difficulty breathing or open-mouth breathing
Home Care
- Remove irritants: if sneezing correlates with a specific cleaning product, air freshener, or other environmental factor, eliminate the trigger
- Humidify dry air: particularly during winter heating season
- For reverse sneezing: gently massaging the throat or briefly covering the nostrils (to prompt mouth breathing and swallowing) often terminates an episode
- Do not attempt to extract nasal foreign bodies yourself: this usually requires sedation and specialized instruments (rhinoscopy)
- Omega-3 fatty acids: may help reduce nasal mucosal inflammation in dogs with allergic rhinitis
Breed Predispositions
- Golden Retrievers: nasal aspergillosis, nasal tumors
- Labrador Retrievers: nasal foreign bodies (enthusiastic sniffers)
- German Shepherds: nasal aspergillosis, nasal tumors
- Beagles: nasal foreign bodies (scent hounds with intense sniffing behavior)
- Brachycephalic breeds: reverse sneezing (common and benign), anatomical nasal issues
Longevity Connection
Nasal tumors, while not among the most common cancers, are locally aggressive and difficult to treat once advanced. However, early detection through prompt investigation of chronic unilateral nasal discharge significantly improves treatment options. Radiation therapy, the primary treatment for nasal tumors, can provide 12-18 months of good quality life when the tumor is diagnosed before it extends beyond the nasal cavity. Dismissing chronic nasal discharge as “just allergies” without veterinary evaluation can delay diagnosis of treatable conditions.
Frequently Asked Questions
What is reverse sneezing and is it dangerous? Reverse sneezing (inspiratory paroxysmal respiration) is a rapid, forceful inhalation through the nose that produces a distinctive honking or snorting sound. It is caused by irritation of the nasopharyngeal area and is common in small and brachycephalic breeds. Episodes typically last 15-60 seconds and resolve spontaneously. It is not dangerous. However, if episodes become very frequent, prolonged, or are accompanied by nasal discharge, veterinary evaluation is reasonable to rule out nasal mites or other structural issues.
Can dogs have seasonal nasal allergies like humans? Dogs can develop allergic rhinitis (nasal inflammation from allergens), but it is far less common than in humans. Most canine allergies manifest as skin disease (atopic dermatitis) rather than respiratory symptoms. Dogs that sneeze seasonally with clear nasal discharge may have allergic rhinitis, but skin allergies should be the primary diagnostic consideration.
When is a nosebleed in a dog serious? Any nosebleed (epistaxis) lasting more than 10-15 minutes, recurring without trauma, or occurring in a senior dog is potentially serious. Causes include nasal tumors, fungal infection, foreign body, clotting disorders, hypertension, and immune-mediated thrombocytopenia. A single, brief nosebleed after vigorous sneezing or minor trauma is less concerning but should be monitored for recurrence.
Should I be worried if my dog sneezes after going outside? Brief sneezing after outdoor excursions is usually from inhaled pollen, dust, or grass particles and is not concerning. However, sudden violent sneezing that starts outdoors and does not resolve within hours could indicate a nasal foreign body (especially grass awn or foxtail), which requires veterinary evaluation.
Can a tooth infection cause sneezing? Yes. The roots of the upper premolars and molars in dogs are separated from the nasal cavity by a very thin plate of bone. When a tooth root becomes abscessed, the infection can erode through this bone, creating a communication between the mouth and nose (oronasal fistula). This causes chronic unilateral nasal discharge and sneezing. Dental radiographs and oral examination under anesthesia are needed for diagnosis.
References
- Plickert HD, et al. “Nasal aspergillosis in 80 dogs: clinical signs, diagnosis, and treatment.” Veterinary Record. 2014;175(6):141-145.
- Lefebvre J, et al. “Computed tomography as an aid in the diagnosis of chronic nasal disease in dogs.” JVIM. 2005;19(3):293-301.
- Tasker S, et al. “Aetiology and diagnosis of persistent nasal disease in the dog.” Journal of Small Animal Practice. 1999;40(10):473-478.
- Malinowski C. “Canine and feline nasal neoplasia.” Clinical Techniques in Small Animal Practice. 2006;21(2):89-94.
This content is for informational purposes only and does not constitute veterinary advice. If your dog is showing signs of illness, consult a licensed veterinarian.