Dogs can eat green apples safely and they are actually a slightly healthier choice than red apples. Green apples, such as Granny Smith, have lower carbohydrates and sugar, and contain more vitamin A, along with other vitamins, making them beneficial in moderation. However, it is important to always remove the apple core and seeds to avoid choking hazards and exposure to small amounts of cyanide in the seeds. Feeding green apple slices or chunks as a treat is fine, but too much apple can cause digestive upset in dogs, so moderation is key.