Hello, need some advice please; went out yesterday morning to let our flock out to free range and one of the girls (8 mos. old) was just laying on the ground and not moving. she would raise her head when I talked to her but she can't seem to stand. Upon closer checking her abdomen seems to be swollen and she has a mustard yellow mess around her vent.... what could be wrong with her and what should I do? Thank you !!!!