I had a terrible experience with my male Boston Terrier and his stinky constant gas explosions and diarrhea. I changed his food constantly which did not solve the problem since I got him in 2010 as a puppy. Finally I said no more so I took him to his vet. After he was weighed and checked, he was found to be overweight.
He was at an obese 37 pounds, where he should be in the 20s. The vet put him on a Royal Canin Veterinarian diet with venison and potatoes. He gets 1/4 to 1 cup of food a day and no treats. He tries not to eat the food, but it is all I give him except a dentastix at night so he has no choice. It has been 3 weeks on the diet and he is down to 33 1/4 lbs. No gas, no diarrhea, and no farting.
I am a happy person and he is a non stinky dog. Now if I could cure his snorting and snoring when he sleeps that would be a winner, but loving him is enough.
Source: My Vet
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Large dogs tend to eat their food too fast and inhale air which causes gas. By placing a tennis ball in the bowl, they must eat slower. This reduces the amount of gas your dogs will have.