Dogs should not eat apple cores. Apple cores contain seeds that have trace amounts of cyanogenic compounds (which can release cyanide), posing a potential toxicity risk especially if consumed in large quantities. Additionally, the fibrous and tough core can be a choking hazard or cause gastrointestinal obstruction. While accidental small nibbles may not cause serious harm, it is safest to remove the core and seeds before giving apples to dogs. The apple flesh itself is nutritious and can be given as a treat without the core and seeds.
