We adopted a 6-7 mnth old dog almost a month ago. Hes a mix terrior. Ever since the first night he has been with us he has coughed. The only way to explain it is he sounds like a cat coughing up a hairball. The foster mom swears he didn't do it when he was with her. Hes on the same dog food as he was with her. Of course I took him to the vet. Hes been on two different antibotics but nothing has helped. We love this dog, he's a great dog but he coughs on and off all night long keeping us up. We want to figure out what's wrong with him because if we don't we will have to give him back.
If anyone has any ideas please we are willing to try just about anything at this point.

A little more info, please.

Does he actually cough anything up?

Did the vet test for infections? Results?

Does he know where water is?

He has plenty of water and does drink it. He does not cough anything up. Hes current on all shots, heart and lungs are clear and no infections.
I do have 2 cats but the foster mom assures me he was around cats at the rescue. The only difference between her house and our house is the cats.

Then I would guess sinus trouble with weather changes or possibly allergies. Our rescue cocker mix gets snuffly when the weather changes, but it doesn't seem to bother her otherwise.

See my husband and I started wondering about the allergies after reading up on them. We have noticed that he does chew on his paws and scratch. Hes such a good dog except for the coughing thing. We haven't slept a full night since we adopted him.
Im thinking of trying Benadryl and see what happens. At this point I figure Im not out anything by trying it.

Did the vet check out his heart?
Coughing can sometimes be a symptom of a heart murmur, I do agree with Cats though it could just be allergies or sinus troubles.

I always say to check with your vet first before giving benedryl just to be on the safe side but it a drug that is OK to give to dogs, the dosage is 1mg per pound every 8 hours or so...
It is however only a short term fix and should not be given long term.

Raw Honey will sometimes help sooth the throat. Give him a big soup spoon of raw honey at breakfast and dinner... If anything, it may make him feel better while you try and figure out the source of his coughing.

His Heart and lungs are all clear. The vet said he looks and seems to be in great shape.
My husband and I are going to try something. Ricky (the dog and no we didn't name him) is going to go spend a couple nights at my sons girlfriends house. We want to see how he is there. If he's not up coughing all night then Im going to say its something for sure in our house.

Yep good idea, let us know how it goes rhnhsh.
Hopefully you can pinpoint the cause soon.