My chickens free range during the afternoon. When my Mini Pin (dog) goes out to do her business she likes to eat the chickens poop. She has never been sick in her 4 years on this earth. But when my chickens were old enough to free range my dog started to get sick now and again. She threw-up a few times and wouldn't eat anything even her favorite treat. After a day or so she's back to normal. I'm guessing its the chickens poop because that's the only new element in her environment. Please give me any advise you can. I have a big back yard where they all doing there business.