I have one chick that had pasty butt right when we brought her home from our local stock shop. I rinsed her bum off in warm water and dried with a blow drier. Now a couple days later she and another one of my chicks have pasty butt. The chicks are about a week old. Im not sure what to do. I check the temperature of the brooder many times throughout the day and they dont seem to be too hot. I have read about apple cider vinegar but am unsure of how much to use. Any suggestions would be greatly appreciated!!!!