Bronchoalveolar lavage cytology from captive badgers

Abstract

Bronchoalveolar lavage (BAL) fluid is evaluated for the diagnosis and study of lung disease and airway inflammation. Cytologic profiles for BAL fluid have not been reported for badgers and may be useful in understanding the pathogenesis of pulmonary diseases such as Mycobacterium bovis. The aim of this study was to evaluate cytologic and microbial findings in BAL fluid from captive European badgers (Meles meles) and identify correlates with the results of concurrently collected blood and fecal samples. BAL fluid (by a nonbronchoscopic method) and jugular venous blood samples (for routine CBC) were obtained from 23 captive tuberculosis-free anesthetized badgers on 2 occasions 4 weeks apart. Fecal samples were collected for routine parasitology. Morphologic evaluation and 100-cell differentials were done on cytocentrifuged BAL specimens. Pellets from centrifuged BAL were aerobically cultured for bacteria. With the 2 BAL samples from each of the 23 badgers combined, the median (range) cell percentages were 73.0% (5-95%) neutrophils, 7.5% (2-16%) macrophages, 8.0% (0-27%) lymphocytes, and 9.5% (0-92%) eosinophils. Macrophages frequently contained silica-like crystals. Other findings included ciliated epithelial cells, goblet cells, mucus, and Aelurostrongylus sp. larvae. A light growth of Streptococcus, Pasteurella, or Escherichia coli was cultured in 6 badgers. Trypanosoma pestanai were identified in blood from 10 badgers and fecal parasites (mainly coccidia) were found in 20 badgers. No correlation was found between BAL and CBC results and the presence of parasites. The predominance of neutrophils in BAL fluid from badgers differs from the predominance of macrophages found in BAL from other species. This difference may reflect the burrowing lifestyle or the unique immune response of badgers.