Is Your Dog Coughing?
As advice goes, this perhaps is a strange one as you have to look at a few elements. Your dog might be coughing because it has kennel cough. (Kennel cough is highly contagious amongst other dogs so please do not walk your dog whilst he has kennel cough) In which case you need to get antibiotics from your vet. Your dog may be coughing because his heart isnt working to full capacity and there may be a build up of fluid accumulating in his lungs which is why he is coughing. This would also require veterinary treatment. As an interim measure you could give honey to soothe your dogs throat before seeking veterinary help. To help monitor his health if you keep an eye on his gums this will give you a good idea of whether he has an infection or if his circulation is working efficiently or not. (see health checks page).
A great article written from personal experience can be found here : Kennel Cough
Another reason as to why your dog has a cough is he might have a foreign body stuck in his throat such as a stick or a blade of grass tickling him. If your dog is clawing at his face in distress or excessive dribbling then he might have something stuck inside his mouth, it could be in the roof of his mouth or between his teeth or right down the back of his throat. If you can see the stick, it is likely to be at the back of his throat in the roof of his mouth - make your little finger into the shape of a hook and attempt to hook it out without pushing it in further. If you are unsure of doing this then please seek veterinary help. If you have been able to remove the stick you can offer honey to soothe the throat or try and make him drink some water to clean the area which may be grazed. If you have been unable to remove the foreign body (stick or grass) or you cannot see what is causing your dog to have excessive dribbling and discomfort then please seek veterinary help!