I have not seen any bloody droppings for the last 24 hours, but it comes and goes so I am still keeping an eye on them. I could not find buttermilk either (everyone is making eggnog?) but I found a can of buttermilk powder at walmart.Thankfully there are other vets around here that don't treat chickens, but will do fecals anyway!
So @SarahGfa I told you I'd be in the same boat, they're on their last day of treatment & still blood. Sending DH out to find some buttermilk today.
How are yours looking today after a couple days of probiotics? I did see in one of the articles @Eggcessive posted that they recommended treating with the antibiotic again 5 days later, at least I think that's what I read, I'll have to go back.