Diarrhea caused by bovine coronavirus and rotavirus in calves is one of the most economically significant health problems on dairy and meat cattle farms. Economic losses are the result of the death of calves, and are contributed by the cost of treatment, additional work around a sick calf, reduced growth and higher consumption of feed for such a calf. Calves that are cured of the disease caused by diarrhea lag behind in growth and development, require more human labor, and in the end profit is lost on such calves. The age of the calf is important in the occurrence of diarrhea, newborn calves are most sensitive in the first month of life, and with age the risk of the disease decreases. Infections are most often mixed and are caused by a group of multiple agents such as viruses, bacteria and protozoa, and can arise as a result of poor management on farms, including mistakes in feeding, poor hygiene, failure to implement preventive measures and other environmental factors. For disease prevention, the most important thing is to adhere to primary and secondary biosecurity measures and to regularly immunize cows and passively immunize calves through colostrum. Zoonotic potential is present in both viruses due to the possibility of mutation and interspecies transmission.