2018 ACVIM Forum Research Abstract Program: Seattle, Washington, June 14 - 15, 2018

However, several electrocardiographic variables may be influenced by factors such as species, age, gender, breed and morphofunctional constitution, highlighting the importance of knowing normal characteristics for distinct species, breeds and development stages. This study aims at assessing the electrocardiographic development in the frontal plane and apical-to-basal derivations during the last days of pregnancy (35, 28, 21, 14, 7 and 1 day before birth) in 10 donkeys of the Pega breed. Therefore, the electrocardiogram was conducted in a computer-interpreted electrocardiography device in the frontal plane and apical-to-basal derivations for 5 minutes without sedatives, tranquilizers or anesthetics. The results are shown in Table 1 . We did not observe physiological or pathological cardiac arrhythmias or electric conduction disorders in the animals assessed. The heartrates observed in frontal plane and apical-to-basal derivations presented minimal changes between the studied moments during pregnancy and the predominant cardiac rhythm observed in 100% (60/60) of the females was sinus tachycardia, with the heartrate increasing as the birth got closer (58±8.47 bpm in the 35 th day before birth and 61,3±11 bpm at birth). Bifid and biphasic P waves were predominant at all moments.