I am a new member of the forum and would like to ask all you chicken experts some advice if I could please. I currently have 1 Isa Brown and 1 Australorp chicken which are both 18 months old. Up till now they have given us a good steady supply of eggs and its great watching them roam the backyard in search of food. Over the last week the eggs that the Isa Brown has laid have long thin lines of blood in the white of the egg. They have the appearance of an blood vessel. What causes this and should I be worried? There have been 3 eggs the same so far in the last week. Its very cold here at the moment but I dont think that should matter. They have been wormed recently (2 months ago), she is still very active and has a good appetite. Her droppings appear normal. Any help or advice would be much appreciated.