According to PawNation, dogs can eat apples safely. Additionally, Modern Dog Magazine states that apples are a very healthy snack for dogs, brimming with goodness.
According to Modern Dog Magazine, apples provide a low-fat, nutritious snack for dogs, due to their low calorie count and high levels of vitamin K, vitamin C and soluble fiber. Dog owners can grate an apple as a dinner topping for a fiber and vitamin boost, or in hot weather, freeze apple slices and give them to their pets as a delicious, cooling treat. However, PawNation and Modern Dog Magazine tell pet owners to avoid feeding apple stems and seeds to dogs because they contain cyanogenic glycosides, which cause stomach upset, and when consumed in large doses are toxic.