I had been letting my dog drink water from my rain barrel system (not anymore) and she caught Giardia. She has been treated but the chickens were drinking the same water and now all of them have diarrhea. I am suspecting they have it too but I have no idea how to treat them. I still have Corid from when they got coccidia when they were younger, but the package does not say anything about Giardia. I don't have an avian vet where I live plus I have heard Giardia is hard to find in fecal samples. I would like to go ahead and treat them but don't know what medicine to buy. I have a tractor supply, a southern states, and a petsmart nearby.