Can puppies eat spinach safely? What's the right way to feed it?

The answer is controversial. Spinach is high in some nutrients, but also high in oxalates, which in sufficient amounts, can block the absorption of calcium and can lead to kidney damage. Most experts agree a dog would have to eat a lot for this to happen, but there is no definitive amount or answer as to how much is too much. Dogs don't require vegetables, but they do sometimes enjoy them. I would ask the advice of your vet about feeding your dog spinach. If they don't have a problem with it, you will have to prepare it especially for your dog for him to obtain the most benefit from it. It should be chopped fine, since dogs intestines are not made to process vegetable matter the same way we are. It should be steamed with nothing added to it at all, no salt, spices, or butter. Boiled spinach has lost much of its nutrition, and raw spinach is too hard for them to digest. Small, infrequent amounts are okay, only if your dog's kidneys are healthy.