Large and Thick Ostrich Dog one. Sizes very but most bones are about 11-12 inches long and 3-4 inches thick. The energetic, wide-eyed ostrich is native to the grasslands of South Africa. Though they are the world’s largest flightless birds, their long legs enable them to run at speeds of over 65 km (40 miles) per hour. Bred and fed a pure and balanced diet in their natural environment, breathing clean air and free to roam through vast areas of territory, the meat of these agile birds is a novel protein, uniquely lean, healthy and very tasty which poses a low risk of food allergies to pets.