Every time an animal squats to poop, it leaves a health report behind. Not in words. In microbes. That sounds like a stretch, but it isn’t. The gut of any mammal carries trillions of bacteria, and when the intestines get sick, those communities shift in ways that turn out to be surprisingly consistent. The part that caught my attention is how far the pattern travels. The same basic shape of disruption shows up in a dairy calf, a family dog, a barn cat, a horse, a goat, a pig, and a person. Intestinal disease is one of the most common and expensive health problems we deal with in animals. Calf…