Comparative electrocardiography in four species of macaws (genera Anodorhynchus and Ara)

Electrocardiograms (ECGs) were recorded during isoflurane anaesthesia from 52 macaws of four species of the genera Anodorhynchus and Ara in order to establish electrocardiographic reference values. The birds examined were clinically healthy macaws of the following species: hyacinth macaw (HM; Anodorhynchus hyacinthinus, n = 14); green-winged macaw (GWM; Ara chloroptera, n = 11); blue-throated macaw (BTM; Ara glaucogularis, n = 15); and red-fronted macaw (RFM; Ara rubrogenys, n = 12). All ECGs were recorded using a paper speed of 50 mm/s and a calibration of 10 mm = 1 mV. Significant differences were determined between species for the heart rate, duration and amplitude of the P wave, amplitude of the T wave, and amplitude of the QRS complex, specially comparing the RFM to the other macaw species. No significant differences were found between two species of similar body weight: the HM and the GWM.