If there were chickens on the dirt before the peafowl, blackhead could be an issue, but you normally see a bright sulfur yellow poo with it.......... They go off food, peck at it but not eat. Stay fluffed up and depressed, start losing weight, face gets a darker hue from poor blood supply , weakness then death. It affects the organs. It is hard to pin point what is wrong since she had other issues before this. keep her hydrated with vitamins and water....... I'm afraid when it is that bad,and they lose a lot of weight, it is very hard to come back from it, even with tube feeding.
