Dogs can eat tofu because it is not toxic to them, but tofu is not recommended to be part of a dog's diet. The type of protein that is present in tofu is not a proper replacement for the protein found in meat necessary for a nutritious dog diet.
Dogs are naturally primary carnivores who need the nutrition found in the meat of other animals to survive. Most dogs foods on the market mimic the nutritional breakdown of this animal's natural diet. It is recommended to feed a dog either a raw meat diet or a dog food brand that lists a protein source as the first ingredient.