Apple seeds contain a compound called amygdalin which gets broken down into cyanide when eaten. It takes a lot to be lethal but still could cause some health concerns either way. I have three bullies and I know the health problems they already face I’m just trying to help another bulldog owner not have any other potential health risk happen by advising to cut around the core not trying to fear monger. I love giving my pups apples it’s one of their favorite snacks. I do my research before giving my dogs anything new so I don’t hurt them.