Research Articlealso useful as prognostic indicator in large animal medicine, and it provides a record of the varying potential difference that occurs over the surface of the body as the result of electrical activity within the heart. In large animals, including buffaloes, a base apex lead has been shown to be an ideal lead system for monitoring cardiac arrhythmias [2]. Recently normal ECG study parameters in adult goats were recorded in Andhra Pradesh [3]. Literature on normal values of different ECG parameters in buffaloes was scarce so, a preliminary study was undertaken on buffaloes using the Base-Apex ECG lead system in Proddatur of YSR Kadapa District in Andhra Pradesh state of India. Materials and MethodsPresent study was conducted in buffaloes (28) which are maintained in well dairy farm and cases presented to the Teaching Veterinary Clinical Complex, in Y.S.R. Kadapa District of Andhra Pradesh, India. Buffaloes in this study were maintained occasional open grazing with green pasture, paddy straw and ad libitum water. All the buffaloes in this study were aged between 4 to 9 years and in lactation period and were clinically examined for soundness before the recordings described by Rosenberger [4]. Buffaloes were apparently healthy and normal at the time of study and all the vital signs were within the normal range and free from the cardiac and other systemic problems. Electrocardiographic parameters recorded in this study were on a bipolar base apex lead, using limb lead I as standard [5]. Same procedure was adopted previously to record the normal ECG parameters in sheep and goats [6,7]. All ECGs were recorded on a three channel electrocardiographic machine (Marks electronics, Chennai) with 25 mm/sec paper speed and calibrated 10 mm/ mV.The right arm electrode was attached to middle of the neck (Figure 1) and the left arm electrode is placed over the apex of the heart just behind the elbow (Figure 2) [5]. Buffaloes were kept in quiet surroundings at the time of recording. The electrodes were placed using alligator clips with a gel contact. In order to ensure good adherence to the skin, the skin was cleaned with alcohol prior to the application of the gel. The recordings were analyzed for the P wave, the QRS complex, the PR interval, the ST segment, the QT interval and the T wave. Heart rate was calculated according to the R-R interval in lead-1. All the data were analysed by using the SPSS software and expressed as mean ± standard error of mean (SE) and range at confidence interval 95%. Correlation coefficient was calculated between the heart rate and QT interval. AbstractElectrocardiographic studies were carried out in healthy adult buffaloes in Proddatur of Andhra Pradesh state in India. The electrocardiograms were recorded in standard base apex lead system. Duration and amplitude of the P, QRS complex and T wave and the PR, RR intervals, ST segment and heart rate were measured and averaged from successive beats. Mean heart rate was 61.175±0.8262 bpm. Mean amplitudes of the P, R and T waves was 0.186±0...