Abstract
On March 29, 1989, an abnormal calf birth occurred in Okayama Prefecture.
The abnormal calf displayed the inability to stand and extended any of its four limbs. From histopathogical findings and results of the neutralization test against Ainovirus, it was suggested that the abnormal birth may have been associated with an infection of Ainovirus. Findings obtained by examinations of sentinel calves suggested that an epizootic of Ainovirus infection took place from September to October, 1988. The antibodies to Ainovirus in the southern area of Okayama Prefecture were examined in serum samples collected from sentinel calves in 1985, 1988 and 1989. These results made it clear that the epizootic of Ainovirus infection occurred in 1985 and 1988. Serum samples were collected from 380 cows on 83 farms during December, 1985 to December, 1989. The neutralizing antibody to Ainovirus were detected in 27.4% of 380 cows.
These results in indicated that Ainovirus was widely distributed in the southern area of Okayama Prefecture.
