My 87 yr old grandmother tried to feed my Schnauzer a prune! She has Altzhiemers, so there is no point even trying to reason with her.I also caught her giving the dog chocolate covered nuts! My Gmother says" HE gets tired of eating the same thing every day" At first I told her it was not a HE but a SHE. After the 10th time I just gave up. so, not only is she feeding my dog garbage, she has given it a sex change! Older people have their own ideas about things. It can be hard to get them to change. I would tell her it is not healthy for boobah, and hope she will understand.Good luck!
