<div>Background: Since many electrolytes are invariably lost in the diarrheal fluid, their serum alterations would have a profound bearing on the ECG.&nbsp; 
 
Methods: The study was conducted on twelve diarrhoeic and dehydrated male bovine calves of 2-5 months of age. Electrocardiogram and some haemato-biochemical parameters were compared between dehydrated and hydrated animals after supportive treatment.&nbsp; 
 
Result: Heart rate was found to be increased from 90.33 &plusmn; 9.71 bpm to 104.33 &plusmn; 9.03 bpm with considerable cardiac arrhythmias in dehydrated animals. Significantly (P&lt;0.05) decreased QRS amplitudes and ST intervals were seen in dehydrated animals, whereas QRS durations were significantly increased. P waves were sometimes flattened or not visible, while T waves often were tall and peaked in diarrhoeic calves. No other significant changes in ECG parameters including cardiac axis were noticed. Non-significant increase in erythrocyte count and haematocrit associated with haemoconcentration was found. There was however a significant increase in lymphocyte and eosinophil count, together with increase in osmotic fragility in dehydrated animals. Electrolytes sodium and magnesium decreased significantly, while potassium increased amongst dehydrated calves. Based on observable ECG changes, alterations were indifferent from those of hyperkalemia, hyponatremia and hypomagnesemia. It is hoped that the present communication would be a helpful guide for the clinical veterinarian or those electrocardiographically monitoring supportive therapy of dehydrated animals.</div>

Electrolyte and Electrocardiogram Changes in Dehydrated Male Bovine Calves

The present study was conducted to recognize by part, the cardiovascular events of the nasopharyngeal reflex, through electrocardiographic interpretations. ECG patterns were traced in twelve clinically normal and healthy New Zealand White rabbits of both sexes, weighing between 2-3 kg and aged between 1-3 years with inhalant irritants. Immediately after induction of formaldehyde vapour, the heart rate fell by 69% from a mean of 192 &plusmn; 7.310 bpm to 60 &plusmn; 1.296 bpm, whereas exposure with cigarette smoke caused a fall in heart rate by 74% from a mean of 205 &plusmn; 9.605 bpm to 53 &plusmn; 3.065 bpm. With both irritants, P wave becomes smaller and totally disappeared, indicating an increased vagal activity inducing a sinoatrial node arrest. The amplitude of QRS complex also significantly decreased; and so did the duration of P wave and PR interval, presumably due to junctional escape. T wave duration decreased with slow ventricular repolarization. Bradycardia was also evident with increased QT interval. However, there was no change in QRS complex or ventricular depolarization, mediated perhaps via compensatory sympathetic influence on the ventricular myocardium. The study demonstrates that both formaldehyde and cigarette smoke provoked a similar protective response of rabbits against noxious fumes. 
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Electrolyte and Electrocardiogram Changes in Dehydrated Male Bovine Calves

Electrocardiographic interpretation of the nasopharyngeal response in conscious rabbits