take the dog to the vet...might be something poisonous they ate...over eating will do that as well or just a case of a cold!
If he does it a lot, then he might have kennel cough, or other type of canine influenza. For that you need the Vet.
yepp! if they start doing it loadz u myt wanna look at taking them to the vets!
take them outside most likley they are going to puke
could have K-9 Cough
take em to a vet