Abstract
The properties of viral agents, isolated during the cowpox-like disease outbreak in Hokkaido, Japan, fall of 1962, were investigated by comparing them with vaccinia and cowpox viruses. The agent which was isolated with difficulty on CAM of chicken embryonating eggs and HeLa cell cultures, were identical to vaccinia virus in several respects, but it was not similar to cowpox virus "Downie" (LB red). The disease of cattle was diagnosed as cowpox from the standpoint of a disease which showed clinical syndrom or entity in cattle affected with pox group of viruses.