Well both Iams and Purina are very low quality foods, so I would suggest switching again. A dog should not regularly have bad gas. I would go to dogfoodadvisor.com and look at the reviews for the Iams and Purina foods you were/are feeding. Next, look through the list of 4 and 5 star foods. I would suggest choosing a grain free food as well.
Also, why is she not allowed to scratch her butt? If she has an itch you shouldn't keep her from scratching it. Can you imagine if you were really itchy and whenever you tried to scratch someone scolded you or reprimanded you?
Also, why is she not allowed to scratch her butt? If she has an itch you shouldn't keep her from scratching it. Can you imagine if you were really itchy and whenever you tried to scratch someone scolded you or reprimanded you?