Electrolyte and electrocardiogram changes in dehydrated male bovine calves

Since many electrolytes are invariably lost in the diarrheal fluid, their serum alterations would have a profound bearing on the ECG.

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.

Heart rate was found to be increased from 90.33 ± 9.71 bpm to 104.33 ± 9.03 bpm with considerable cardiac arrhythmias in dehydrated animals. Significantly (P<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.