One of my friends swears that putting her dog on a vegetarian diet cured him of his flatulence. I would have thought it'd be the other way round, tbh, and even though I'm a committed veggie I don't think I'd inflict it on an animal who doesn't understand it. But it might be worth trying him on veggie dog food? Not sure where you'd get it in Ireland mind...
Yeah, I knew a chick who put her dog on a vegetarian diet.
And then wondered why the dog ran around eating other dog's dogshit.