Hi all I have two Australorp (15 weeks) that started limping and developed yellow pads and the backs of there legs are yellow too. The frist one has a limp and the pads and back of her leg on one side are yellow, her foot is slightly swollen. (1 week) The second one started limping and one leg was yellow (pads and back of her leg), two days later both legs were yellow. (3 days) Whats causing this? Will it spread? ??? THANK YOU.