Kennel cough if its been around other dogs and you do not vaccinate
It could be a number of things and internet search is not a good way to go about it. I would suggest you take him to the vet. Make sure to make a appointment sometimes or most of the time they won't see you with out one.
Could be allergies.
I'm in agreement with Donna... Ask a professional. Hope all turns out well.
It's something you should take them to the vet for. Since dog's don't normally cough.
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