Today I cracked an egg open and there was a substantial blood spot--I wish I'd gotten pics. It spread out over the surface of the yolk in a bright red, nickel-sized circle. One of our hens was attacked by a dog last year, and has been limping and underweight ever since--I wonder if she laid the egg, if maybe its a sign that something else is going on w/her? We have 4 hens, and they all lay brown eggs, so I am not sure which one laid it. Is this abnormal? Is it a sign of a health problem? Any advice would be welcome!!