Dogs can have spinach, but only in small amounts and not regularly. Spinach is a superfood rich in vitamins A, B, C, and K, iron, beta-carotene, antioxidants, and fiber, which can provide health benefits such as improved skin, coat, eyesight, immune support, digestion, and muscle health. However, spinach contains oxalic acid, which can interfere with calcium absorption and potentially cause kidney damage or stomach upset if fed in large quantities or too often. It is best to feed dogs cooked spinach (steamed or blanched) without any additives like butter, oil, onions, or garlic. Raw spinach is harder for dogs to digest but can be given occasionally in small, chopped pieces. Avoid canned spinach due to its high sodium content. Dogs with kidney issues or puppies should avoid spinach. Always introduce spinach slowly into their diet and consult a veterinarian first. Spinach should be an occasional treat, not part of daily meals.