Stress can impact the body in many ways, such as causing headaches, upset stomachs, and making people more likely to get sick. Newly weaned calves, which have been separated from their mothers and given a grain-based diet, can also feel stressed, increasing their risk of illness, according to veterinarians from Kansas State University on the Beef Cattle Institute’s Cattle Chat podcast.

One common illness that can affect these calves is coccidiosis, caused by a tiny parasite that damages the intestinal wall. While these parasites are usually found in the environment, stressed calves are at higher risk. A major symptom of this infection is bloody diarrhea.

K-State nutritionist Phillip Lancaster explained that when calves switch diets, their stools may become looser but still have some form. However, calves with coccidiosis have watery, dark stools due to blood in their intestines, which healthy calves don’t experience when changing to a grain diet.

For beef producers who think their herd might have this issue, K-State veterinarian Brian Lubbers recommends starting with a fecal sample for diagnosis. He also stressed the importance of working with local veterinarians to find the right treatment and to adjust management practices to reduce the risk of future outbreaks.