Apples are a healthy and enjoyable treat for dogs. Loaded with calcium, vitamin C, vitamin K and soluble fibre, apples can be sliced and frozen, inserted into a toy or grated over dinner. However, dogs should not ingest apple seeds or stems, as these contain cyanogenic glycosides, which cause stomach problems and some serious health problems if consumed in large amounts. Dehydrated apples can upset the stomach.
In addition to being mildly toxic for dogs, the apple seeds and stem are choking hazards. Although a few seeds are unlikely to harm dogs, the accumulated effect over time can have serious effects on their health. However, as long as the seeds pass through unbroken, dogs should remain unaffected.
Apple slices can help clean a dog's teeth, helping freshen his breath. Too many apples can cause diarrhea or loose stools, however. Apples are roughly 52 calories each; when given as a treat, apples have a negligible effect, but allowing dogs to snack continuously on apples can lead to weight gain. While the calcium in apples is healthy, dogs with kidney problems react poorly to calcium and should not be fed apples. However, the vitamin C is thought to help prevent or treat hip dysplasia, a common health problem in older or larger dogs.