Clinical and microbiologic findings in dogs with bronchoscopically diagnosed tracheal collapse: 37 cases (1990-1995)

To investigate the role of bacteria in bronchoscopically diagnosed tracheal collapse in dogs by evaluating qualitative results of bacteriologic cultures.

Retrospective study.

37 dogs with tracheal collapse.

Clinical records for dogs with tracheal collapse confirmed with bronchoscopy were reviewed. A protected catheter brush was used to obtain samples for bacteriologic culture from the large airways.

Results of bacterial culture were negative for 5 of 29 dogs. For 24 dogs, 1 (n = 10), 2 (6), or > or = 3 (8) species of bacteria were isolated. Pseudomonas spp were isolated most frequently (17/29), and a single Pseudomonas sp grew in 7 samples. Other bacteria included Enterobacter spp (4/29), Citrobacter spp (3/29), and Moraxella spp, Klebsiella spp, Bordetella spp, or Acinetobacter spp (2/29 dogs each). Anaerobic and aerobic cultures yielded positive results in samples from 2 dogs. Cytologic results were available for 13 dogs with positive results of bacteriologic culture; epithelial cells were reported most commonly. Five samples had a small number of neutrophils; bacteria were identified cytologically in 2 of 5 samples that contained neutrophils. Bacteria were also seen in 2 samples that lacked inflammatory cells.

Bacteria are commonly isolated from samples obtained via airway brushing in dogs with tracheal collapse; however, in the absence of cytologic confirmation of inflammation or infection, an association between bacteria and clinical signs of tracheal collapse cannot be established.