I have a rouen hen that vomited once yesterday that I witnessed. It was brownish water. She is acting lethargic and weak. When she tries to walk she stumbles after a while. She had something similar happen about 5 weeks ago. But I never seen her vomit. She stopped laying eggs the last time. I thought her mate was over mating her. But since she recovered and went back outside with him he hasn’t mated her much. She has been drinking I don’t think eating. I have her in the bathtub with electrolytes and wet food. None of my other ducks are acting sick or like her.