An egg is a completely balanced protein. It has all 22 amino acids. However, exclusive reliability on only eggs will cause various health issues. Your dog should not get her protein from egg only sources. When you cook the egg, the egg white contains enzyme inhibitors, which can later create protein deficiencies and may lead to protein absorption issues. Make sure you limit it. Use it as a way to bump up your dog's protein as a snack for a few days a week.