Normal electrocardiogram patterns and values in Muscovy ducks (Cairina moschata).

To describe normal electrocardiographic parameters in conscious Muscovy ducks (Cairina moschata), standard bipolar (I, II, and III) and augmented unipolar limb (aVR, aVL, and aVF) lead electrocardiograms were recorded in 10 clinically healthy birds. Wave forms were analyzed in all leads at 50 mm/s and at 10 mm= 1 mV to determine PR, QRS, ST, QT durations; the net QRS complex; and P and T amplitudes. The polarity of each waveform was tabulated in all leads. The mean electrical axis (MEA) for the frontal plane was calculated by using leads II and III. The mean (SEM) heart rate calculated from lead II was 146.6 - 6.8 beats/min. The P wave was predominantly positive in all leads. The dominant pattern of waveforms of the QRS complexes was rS in leads II, III, and aVF, whereas, in leads aVR, and aVL, the pattern was R. The T wave was positive in leads II, III, and aVF and was negative in leads aVR and aVL. The mean (SEM) of the heart MEA was -91.2 2 1.8. The electrocardiographic values and patterns tabulated in these clinically normal Muscovy ducks should provide a means of comparison to aid in the diagnosis of pathologic abnormalities in this species.