Dogs with runny nose and eye mucus may be caused by colds, rhinitis, sinusitis, viral infection, etc. You need to first observe whether the dog's condition is serious and whether there are other symptoms. If it is serious, it is best to take the dog to the Check and treat the dog at the pet hospital. If it is just a mild cold, you can give the dog special cold medicine for pets. At the same time, adjust the dog's diet and feed it some light and easy-to-digest food.