Sneezing in dogs, like in humans, has many causes. When the sneezing becomes persistent, it is possible that the dog has an underlying illness causing the sneezing. A veterinarian can examine and diagnose a sneezing dog, as well as recommending the best course of treatment.
According to the Dog Owner's Guide, dogs sneeze from excitement or nervousness as well as because of illness. The more often the dog sneezes, the more likely there is an underlying problem causing the sneezing.
Causes of persistent sneezing in dogs include respiratory infections, an inhaled foreign body, tumour, polyp, allergies, distemper, kennel cough and sinus infection. Persistent sneezing combined with a runny nose suggests a foreign object in the dog's nasal passages, allergies, respiratory infection or a tumour. Nasal discharge can also suggest sinus infection, distemper or kennel cough.
Occasional sneezing is normal in dogs, just as it is in people. The more frequent the sneezing, the more likely the dog has a medical condition. Dogs that sneeze persistently for more than a day, or which develop trouble breathing, should see a vet to determine the cause of the sneezing.
Sneezing by itself does not necessarily suggest a medical problem. Persistent sneezing accompanied by other symptoms could signify illness. According to PetPlace.com, other symptoms to watch for in a sneezing dog include gagging, reverse sneezing, bleeding from the nostrils, bad breath, swollen nose, laboured breathing, loss of appetite, weight loss and lethargy. If your dog has any of these symptoms, see a vet.
According to Dr. Ron Hines, sneezing is often caused by a bacterial infection. The best way to protect a dog from a bacterial infection is to keep it away from other infected dogs, especially kennel-like environments. Sneezing caused by viruses such as distemper are preventable through annual vaccinations.