I read posts on this back 10 pages worth but wanted to seek any additional advice. Back in Jan. one of my hens, age 4, turned up with a messy butt. She is one of 39 birds. I have had this flock for 5 years and didn't do anything different over the winter. It was very wet here in MI this winter, though. They have wood shavings as their bedding and eat pellets as food. I mix oyster shells and grit into their pellets plus I have feeder filled with a mix of this in the coop. Since it was winter, they did not free range outside of their chicken yard and I gave them very little in the way of treats- a few scraps of dried bread and maybe some mac/cheese and rice. They get organic vinegar in their water and some vits/electrolytes. I also gave plain yogurt a couple of times as a probiotic hoping to right their systems. As time went on she became more listless and died last week. I felt bad, like I should have done more to help her. I didn't notice any swelling of the crop or vent area. A couple of weeks ago three other hens turned up with a messy bottom and so I'm worried about them, too. Last week I took a fecal sample to my vet and supposedly there were no parasites. I read a post about providing scrambled egg, yogurt, mash to try to right their systems. Also, check for lice. What do you think? Does the fecal test at the vet pick up Any and All worms? I hate to routinely worm them but should I worm them and if so, what should I start with? I think I would prefer to offer some probiotics but I'm afraid if it's more than that, this won't help. I will check for lice. I have checked for blood in the droppings over the past several weeks but I have not seen any. I'm worried this will eventually affect the whole flock. I'm asking for your expert advice. Thanks so much.