Bronchoalveolar lavage cytology and hematology: a comparison between high and low health status pigs at three different ages

School of Veterinary Medicine, Department of Medical Sciences, University of Wisconsin, Madison, USA. Bronchoalveolar lavages (BALs) were performed with a bronchoscope on 5- and 7.5-week-old, anesthetized, high health status pigs (n = 14). At 10 weeks of age, pigs (n = 28) were necropsied, lungs were removed, and BAL samples were collected from the right diaphragmatic lobe with a modified 12-Fr (4-mm) Foley catheter. Peripheral blood was sampled from all pigs (n = 28) before each BAL procedure. Peripheral blood and BAL samples were collected according to a similar study design at 5, 7.5, and 10 weeks of age from 12 low health status pigs, which were raised according to standard farm procedures (n = 6) or as segregated early weaned pigs (n = 6). Bronchoalveolar lavage cytology and hematologic 95% confidence intervals were determined for 5-, 7.5-, and 10-week-old high (group A) and low health status pigs (groups B and C). The results were compared between the different groups. Repeated BALs were easily performed in all pigs, making this an additional tool for evaluation of respiratory health. Total numbers of cells and neutrophils in peripheral blood and BAL samples were greater in low health status pigs than in high health status pigs. Hematologic results paralleled the findings in BAL fluid. Segregated early weaning of low health status pigs in a less challenging environment mainly reduced the number of neutrophils in BAL samples and peripheral blood.