EVALUATION OF RESPIRATORY INDUCTANCE PLETHYSMOGRAPHY IN HEAVES-AFFECTED HORSESByAshley BehanRecurrent airway obstruction (RAO) is an airway disease that becomes clinically evident in susceptible middle-aged horses. The obstruction by bronchospasm and excess mucoid secretions is a consequence of inflammation that occurs within a few hours of inhalation of organic dust. The onset and progression of the disease is difficult to monitor with the standard methods used to assess pulmonary function in horses. Therefore, the main objective is to use non-invasive respiratory inductance plethysmography (RIP) to investigate differences in breathing pattern between control and RAO-affected horses during the onset of airway obstruction induced by stabling. Pulmonary function indicated airway obstruction in the RAO groups on the final two days of stabling. The values for RIP (RIPf and RIPtd) did not differ between groups, but the standard deviation of these decreased significantly within eight hours of the onset of stabling in RAO-affected horses. RIP output and pulmonary function were highly correlated as severity of disease progressed. The decrease in standard deviation of RIP output indicates decreased breathing pattern variability in RAO- affected horses. This loss of variability may provide an early indicator of airway inflammation.
Read
