Cilia-associated respiratory (CAR) bacillus infection in veal calves and adult cattle

Cilia-Associated Respiratory (CAR) bacillus is a filamentous bacterium that colonizes the ciliated epithelium of the respiratory tract of many animal species and that has been associated with chronic inflammatory lesions in n aturally and experimentally infected rats, mice and rabbits. In the present study, the prevalence of CAR bacillus infection and histological lesions o f the trachea in veal calf and adult cattle were investigated., Forty five healthy veal calves and 45 adult cattle, raised in 18 different herds were selected at slaughter. From each animal, a tracheal sample was processed fo r histology, stain-ed with the Warthin-Starry method to evaluate the presen ce of CAR bacillus, and with haematoxylin and eosin to evaluate the presenc e of inflammatory lesions. CAR bacillus was identified in 17 veal calves (3 7.7%) and in 7 adult cattle (15.5%). Inflammatory are available on the prev alence of the in lesions were found in 42 veal calves (93.3%) and in 41 adu lt cattle (91.1%). Statistical analysis pointed out a significant correlati on between the presence and number of CAR bacilli and the presence and numb er of lymphoid follicles (P = 0.0071) and the presence and severity of neut rophilic infiltrates (P = 0.0428). These results indicate that CAR bacillus infection is common in cattle and is correlated with tracheal inflammatory lesions.