Ok, I got one of them too, I have an overweight Lab. I dont think he even has ribs. I attempted to put him on diet food. He liked it well enough but it make him crap 4+ times a day. I live on the 3rd floor in Govt housing so I have to not only walk him the extra times but have to clean it up immediately after him.
He certainly didnt lose any weight but I did from all the extra walking!
