Samimi, A. S., J. Tajik, S. M. Aghamiri & A. Karimi, 2018. A serial evaluation of electrocardiographic indices and cardiac arrhythmias during pregnancy, lactation and dry periods in Saanen goats. Bulg. J. Vet. Med., 21, No 1, 59–66.

DOI: 10.15547/bjvm.1010

Aim of this study was to investigate the effects of lactation, pregnancy and dry period on electrocardiographic (ECG) parameters and cardiac arrhythmias in the Saanen goat. A total of twenty female adult clinically healthy Saanen goats 3 years of age with a body condition score of 3.5 and average weight of 30.2±2.20 kg were randomly selected. The whole duration of the study (8 months) was divided into four periods including dry and non-pregnant (P₁), 2  months pregnant (P₂), 4 months pregnant (P₃), and lactating (P₄) periods. In late pregnancy and lactation periods, the amplitudes of P, QRS and T waves were significantly higher compared to other periods (P<0.01). P-R, Q-T and R-R intervals in late pregnancy were significantly shorter and heart rate was significantly higher than those in other periods. Sinus arrhythmias were the only irregularity observed on the ECG traces and were diagnosed in 30%, 15%, 20% and 35.25% of the goats in P₁, P₂, P₃ and P₄, respectively. There were no significant difference in configuration of ECG waves and cardiac arrhythmias among different periods. Based on the results of the present study, it was concluded that although no cardiac morphological changes have been reported in goats during the lactation, late pregnancy and dry periods, significant changes in ECG parameters were observed in base-apex lead in Saanen goats during late pregnancy and lactation periods. The physiological cardiac arrhythmias and variations in ECG parameters observed during different periods in the current study can be used as a base to achieve more accurate diagnoses of heart diseases using ECG.

Key words: cardiac arrhythmias, electrocardiographic indices, dry period, lactation, pregnancy, Saanen goats