Want a strong and healthy pup? You can have your very own canine Popeye if you feed him spinach. This nutrient-dense green contains twice as much iron than many other greens [source: BARF Diet]. This leafy green vegetable is also a good source of fiber, calcium, potassium, and vitamins A, B6 and K.
Spinach is particularly good for dogs who need to ward off inflammatory and cardiovascular problems as well as cancer. The flavonoids and carotenoids contained in spinach work as anti-inflammatory and anti-cancer forces. Studies on animals have shown that spinach extract can reduce rates of skin cancer [source: World's Healthiest Foods].