dog farts

why do they smell so bad??? wife and i were watching tv the other night and our queensland heeler was on my wifes chair with her. she, the pooch not the wife, let one loose:fart:. damn near had to vacate the house. she has been on the same food, Iams, since we have had her. several times a month 1 of the 3 will gas us out so bad you almost want to vomit.....:vom: