There is a chance that your dog is suffering from Kennel. This disease is a cause of cough in many dogs. Another reason of cough in your dog can be Heat worm that is causing difficulty in breathing as well. Cough can lead to high temperature as well so check temperature of your dog regularly till your dog regain its health. Many medicines are available in market regarding these diseases but it is better if you get your dog checked by its doctor to avoid any further problem.
My poodle is going to be 4 years and it has been having these episodes for the last 2 weeks, could it be something normal in poodles when they are getting older or maybe it was that I painted the inside of the house and has develop an allergy that affected her bronchios or trachea, she is approximately 5 1/2 pounds.
Coughing at rest is associated with heart problems (sometimes failure), trachea issues and lung problems.