An occasional sneeze from a dog is nothing to be concerned about. However, sudden severe sneezing, continuous sneezing or sneezing that produces bloody or irregular nasal discharge, or is accompanied by other physical symptoms, is cause for concern. Pay attention to sneezing that occurs with unusual breathing patterns or breath sounds or that manifests with a swelling of the nose, mouth or facial area.
Allergies or Irritants
Dogs can be susceptible to allergies or to environmental irritants that result in sneezing. This can range from dust and pollen to indoor irritants such as cleaning products or aromatic sprays. If your dog begins to sneeze, take into consideration his surroundings and try to narrow the source of the problem and remove or alter it. If this isn't successful, or if sneezing is continuous, seek a vet’s attention to get to the heart of the matter. Antihistamines may be prescribed as treatment.
Environmental Pollutants and Smoke
Dogs who live in cities with high pollution levels or who live by high traffic areas may sneeze because of environmental pollutants and impurities in the air. Help curb this by walking your dog in areas other than busy traffic ways with continuous car exhaust or keep your dog inside on days weather reports indicate heavy smog. Also be aware that dogs are affected by secondhand tobacco smoke and should not be exposed to cigarettes, cigars, pipes or other tobacco products. Exposure to these carcinogens can result in respiratory problems as well as cancer, particularly in the nose, mouth and throat. Short-snouted dogs are particularly susceptible to these medical conditions.
Respiratory Illness and Stings
Some respiratory problems are characterized with sneezing as a symptom and should be investigated by a vet. Abnormal sneezing with bloody or abnormal, yellow nasal discharge can be signs of an underlying medical problem. Sneezing also can be a sign that your dog was stung by an insect or bitten by a snake. Check his face, nose and mouth for signs of swelling, inflammation and redness.
If something becomes lodged in your dog's nose or nasal passageway, he may sneeze repeatedly as a way to try to dislodge it. According to WebMD, sneezing with head-shaking or nose-pawing is often a sign of a foreign body in the nose. Use a light to look inside your dog's nose or cover one nostril, then the other, to assess breathing. Employ a trained medical professional to help remove foreign objects.