Observations on outbreaks of respiratory disease in housed calves--(1) Epidemiological, clinical and microbiological findings.

In 47 of 50 outbreaks of respiratory disease in indoor calves which had never been to grass there was clinical evidence of pneumonia in all animals examined. Calf housing was in most cases considered unsatisfactory. Virus activity was detected in 70 per cent of outbreaks investigated within a few days post onset of respiratory signs. Parainfluenza (PI) 3 and respiratory syncitial virus (RSV) were the viruses most frequently involved. In the majority of outbreaks Mycoplasma species and Pasteurella multocida were present in the upper respiratory tract of affected calves.