I have an 8 year old German Shepherd. Lately he has been clearing a room more often than he used to. It is becoming really gross. He farts, then leaves to go to the other side of the house because it smells so terribly. When I come home from a long day the last thing I want to do is come home to the smell of lingering dog fart.
What food is he eating? It could be it's not agreeing with him for whatever reason and he just needs a switch. My dog used to eat Taste of the Wild bison and venison, but it gave her terrible gas, so I switched to lamb and now she has only occasional gas.
You could also ask the vet at his next check-up if there's something they recommend for dogs? Like a doggie Gas-X or Beano...I'm sure there is something like that around.