This pilot study had a small number of participants, and the dolphins had fewer combined coughs in 2024 than previous years.
Nevertheless, there was a significant positive correlation between coughing frequency and expiratory duration when including all data.
However, the correlation rely on one dolphin’s spirometry data point during one peak in coughing frequency and prolonged expiration, but simultaneous changes in other inflammation-related parameters suggest it is likely not a coincidence.
I propose that seasonal coughing may be linked to poorer air quality when dolphinarium human activity peaks.
Prolonged expiration in dolphins suggests obstructive, rather than restrictive, pulmonary disease, with more frequent coughing.
Other spirometry studies in humans and horses show similar results, linking poor air quality to Chronic Obstructive Pulmonary Disease (COPD) and increased coughing (Altalag et al., 2019; Couëtil et al., 2001; Torén et al., 2021).
Fahlman et al. (2025) demonstrated that spirometry can accurately predict respiratory health in bottlenose dolphins. Our study, however, shows the potential for detecting disease-specific changes in lung function.
Furthermore, the results could improve animal welfare by facilitating early detection of pulmonary disease and monitoring pulmonary function changes in dolphins in managed care.