what is causing my dog to have a deep rasping cough?

My dog is having coughing fits, but my vet is booked completely through the end of the week. I don't want my dog to cough the way he is coughing until monday, so I am open to suggestions. He is current on all his shots, including kennel cough/bordetella. It sounds like he is trying to cough something up but I reached down his throat as far af possible (without losing my hand) and have not felt any obstructions. All suggestions pertaining to this issue are welcome.

take it to the vet ASAP!!! and if he says it is fine when it isn't then change vet and be careful and remember any slight different activity can be fatal so check and be aware at all times but if the vet

Coughing can be indicative to to cardio problems, including Congestive Heart Failure. Another thing that comes to mind is Heartworm.