There are other viruses that can affect the respiratory system which can lead to a runny nose and cough. A common viral cause (usually has a bacterial component as well) is canine cough. This is sometimes known as ‘kennel cough’ although this can be misleading because dogs can certainly catch canine cough outside of a kennel environment as it is very contagious.
Canine cough usually causes a cough that sounds like your dog has something stuck in their throat. In fact this is a common presentation ‘dog has something stuck in throat’ – that turns out to be canine cough. It is a dry, retching cough that can be followed by gagging.
Other common causes of a cough in older dogs include canine bronchial disease and cardiac disease. Less commonly a cough can be due to heartworm, pneumonia or neoplasia (cancer). Other common causes for a runny nose include allergic rhinitis, dental disease, nasal foreign bodies and neoplasia (however, the latter usually causes a unilateral and more profuse nasal discharge). If you are concerned about sneezing, some common causes include allergic rhinitis, dental disease and nasal foreign bodies.
If you are concerned about your dogs coughing you should consult with your veterinarian immediately to determine the cause and a suitable course of treatment.