PATHOLOGICAL AND IN-SITU HYBRIDIZATION FINDINGS IN CALVES EXPERIMENTALLY INFECTED WITH BOVINE ADENOVIRUS TYPE-4

Three colostrum deprived calves were inoculated intravenously with a s train of bovine adenovirus type 4 (BAV-4) isolated from a calf with ac ute fibrinous enteritis. The calves were monitored clinically and subm itted to post mortem examination at 5, 6 and 10 days post inoculation (p.i.) respectively. The 3 animals showed raise in temperature and dia rrhoea. Acute enteritis was observed in calves submitted to post morte m examination at 5 and 6 days p.i. In these animals viral DNA was spec ifically detected on histological sections by an in situ hybridization (ISH) technique; BAV-4 was isolated from most of the organs and numer ous adenovirus-positive endothelial cells were present in the gastroin testinal tract, mesenteric lymph nodes and liver. In the calf examined 10 days p.i. no lesions were observed and rare ISH positive cells wer e detected. These results indicate that in experimental conditions our strain of BAV-4 is capable to induce clinical signs and lesions simil ar to those reported in field cases.