Hello there! My name isXXXXX and I am sorry to hear about Oliver and his coughing. There are quite a few things that could be causing him to cough with his breed and age. The first couple things I think of that should be ruled out are kennel cough (infection of the trachea caused by either a bacteria or a virus), collapsing trachea (rings of the trachea start to wear out and the trachea closes up some causing him to cough), or a heart disorder that could be causing the cough. So the absolute best thing to do is have him examined to help rule in and rule out a couple things. If he is breathing normally otherwise and doing ok tonight then he does not have to be rushed into the vet but I would plan on having him seen tomorrow. A good thorough exam will help determine if the heart is functioning properly, if the trachea is irritated and if he has a fever or anything. Also an x ray of his chest will help also diagnose this and then he can be treated appropriately with antibiotics or cough suppressants, etc. . . tonight to help calm him down you can give a little benadryl at a dose of 1 mg per pound every 8 hours. That may help calm the cough down a little bit and help him sleep.