Pulmonary function testing as a diagnostic tool to assess respiratory health in bottlenose dolphins Tursiops truncatus

Abstract

Pulmonary function testing was performed in 3 bottlenose dolphins Tursiops truncatus (1 female and 2 males) under managed care during a 2 yr period to assess whether these data provide diagnostic information about respiratory health. Pulmonary radiographs and standard clinical testing were used to evaluate the pulmonary health of each dolphin. The female dolphin (F1) had evidence of chronic pulmonary fibrosis, and 1 male (M2) developed pneumonia during the study. Pulmonary function data were collected from maximal respiratory efforts in water and from spontaneous breaths while beached. From these data, the flow-volume relationship, the flow measured between 25 and 75% of the expired vital capacity (mid forced expiratory flow, FEF25%-75%), and the percent of the vital capacity (VC) at the peak expiratory flow (%VCPEF), were evaluated and compared with the diagnostic assessment. For maximal respiratory manoeuvres in water, there were no differences in FEF25%-75% or %VCPEF, and the flow-volume relationship showed a consistent pattern for F1. Additionally, FEF25%-75% and %VCPEF decreased by 27 and 52%, respectively, and the flow-volume relationship showed clear flow limitations with emerging disease in M2. While spontaneously breathing on land, M2 also showed a 49% decrease in %VCPEF and changes in the flow-volume relationship, indicating flow limitations following the development of pneumonia. Based on these preliminary results, we suggest that pulmonary function testing should be given more attention as a non-invasive and possibly adjunctive diagnostic tool to evaluate lung health of dolphins under managed care and in the wild.