Electrocardiographic measurements in Santa Inês sheep

Abstract

The absence of normal reference values and electrocardiographic standards for clinically healthy sheep of a particular breed can hinder the detection of various conditions that might affect the transmission of cardiac impulses. This study aimed to determine the values of electrocardiographic measurements in leads D1, D2, D3, aVR, aVL, aVF, V1, V2, V3, and V4 and the effects of age and weight in ewes. The study was conducted with 39 nonpregnant and healthy Santa Inês ewes. They were categorized into four groups according to body weight: 7 ewes (20–30 kg), 14 ewes (30–40 kg), 11 ewes (40–50 kg), and 7 ewes (over 50 kg). There were also categorized into three groups according to age: 6 ewes (10–12 months), 28 ewes (16 and 17 months), and five ewes (2–4 years). Ewes aged 16 and 17 months showed a significant increase in P-wave time compared with ewes of other ages. There was no significant variation in terms of weight among the animals studied (P > 0.05). The reference intervals of electrocardiogram parameters did not show considerable variation in relation to weight and the age range from 10 months to 4 years. This corroborates the standardization of electrocardiographic normality values of unsedated Santa Inês ewes.