Clinical signs, gross findings, cardiac histopathology and results of ALV isolation in chickens.

aM: male, F: femalebThe degree of hypertrophied cardiomyocytes with atypical nuclei was defined as follows: +, individual cells; ++, multiple and/or small clusters; +++, multiple and extensive growth.cThe degree of non-suppurative myocarditis was defined as follows: +, focal or multifocal (under 25 µm in diameter); ++, multifocal (from 25 µm to 200 µm); +++, multifocal (over 200 µm).dThe degree of fibrosis was defined as follows: +, interstitial; ++, multifocal interstitial (under 400 µm in diameter); +++, multifocal interstitial (over 400 µm in diameter).eTotal number in 10 high-power fields.f+: positive,−: negative,ND: no data.