I think pig ears in excess is a bad idea, but I've given them to all the dogs I've had. I'm sure the digestion isn't the easiest thing on a tummy. Bully sticks/raw hides get the hairy eyeball from my vet too. Grace has never had a problem with digesting them, but recently I was searching for answers to blood in her urine and thought it might be the raw hide she had spent 10 hours eating. I hid them from her and haven't given them back to her and actually think the blood was caused by a medication she was taking.
I feel bully sticks in moderation are great. Too many cause weight problems and possibly stomach issues. One of the vets Grace sees (I call him the Dog Nazi since he has strong objections to most anything dogs like) caves in and tells me to be stern and not give her treats, expecially raw hides, in excess.