| We tried microbiological and pathological examination of 89 weaned pigs
(aged 2 to 4 months old) from 13 farms located in 4 prefectures to investigate
the present condition of pneumonia in young pigs in Japan. Pneumonic lesions
were found in 81 pigs (91.0%). Although porcine circovirus type2 were detected
in almost all samples (96.0%), only 7 samples showed typical pathological
findings. Porcine reproductive and respiratory syndrome virus (PRRSV),
Mycoplasma hyorhinis and M. hyopneumoniae were often detected at the ratio of 58.0% (29/50), 53.5% (38/71) and 21.1%
(15/71), respectively. Pasteurella multocida, Escherichia coli and Streptococci were sometimes isolated. Species of bacteria detected
were different depending on the farm, except for M. hyorhinis. Nearly half of the pneumonia in the weaned pigs examined were considered
to be porcine respiratory disease complex, recently defined in North America
(U.S.A. and Canada) caused by PRRSV infection together with other opportunistic
pathogens. (Clinical Epidemiology Section, Department of pidemiology TEL
+81-29-838-7798) |