Hi,
Sounds like he has a simple cold. Though it could be a upper respiratory infection which can be serious in dogs. Try taking him in the restroom and running hot water so the steam will help loosen up any congestion. You can start feeding him a bland diet of Boiled chicken and rice to settle any nausea he may experience from this. Make sure he is getting enough fluids so he doesn't become dehydrated.
Should he become lethargic or seems to have difficulty breathing he will need to see the vet. I would call the vet now to be on he safe side as he knows your dogs medical history. He can also prescribe any needed antibiotics. And eye drops to make him more comfortable.
I hope he is feeling better soon.
Walter
Breeder
Breeder and pet health consultant. Have spent a number of years with dog rescue, training and health