We have always given raw carrots to our greedy labs as a healthy snack and the occasional slice of apple.
Seem to recall that the apple itself is fine. I think the pips themselves contain something toxic/poisonous. Seem to remember cyanide

..... might not be that though.

Think they would have to consume a large quantity to cause a problem even if it were that. I know a couple of people that eat the entire apple, including core and pips

and does them no harm.
My neighbours greedy lab has an apple a day ..... and he is ten and looking good.

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