According to PetMD, cooked eggs are an acceptable food for dogs. Hard-boiled eggs are preferable because ingredients such as butter are not needed to prevent eggs from sticking to the pan. Eggs served in chunks, mixed with kibble or whole are suitable, depending on the dog.
PetMD indicates that eggs are a good source of protein needed for muscle growth, healthy hair and tissue repair. Dogs get protein and calcium from eggshells as well, and these strengthen bones and teeth. Some dogs are able to handle whole, unbroken hard-boiled eggs, but others must have the shells cracked or even removed and added to other food. Raw eggs are not suitable for dogs due to the possibility that they contain pathogens that cause illness.