Prof. Mohamed Mohamedy Ghanem :: Publications:

This study was carried out on 29 calves, 2-4 months of age at the faculty of Veterinary Medicine, Benha University during the period from Dec 2010 to March 2012. Based on the clinical findings and biochemical determination of Mg level, the calves were assorted into 3 groups. The first group included 10 calves with tetanic hypomagnesemia (clinical hypomagnesemia,). The second group included 14 calves with non-tetanic hypomagnesemia (Subclinical hypomagnesemia). Five calves from each group were subjected to further biochemical analysis of serum, ruminal fluid and CSF and electrocardiographic changes. A third group (n=5) included apparently healthy calves were used as a control. Therapeutic response of the tetanic and non-tetanic groups was assessed after SC injection of 2 ml/kg BW 20% magnesium sulphate combined with IV injection of 100 ml Cal-Bor-Mag, oral 2 g Mg sulphate and IM injection of 0.1mg/kg BW xylazine (tetanic group only) daily for 5 days. Clinical findings of clinical hypomagnesemia included tetany, opisthotonos, star gazing, episodes of convulsions with erected ears, extension of head and neck, erected tail, widening and rotation of the eye ball and dilatation of nares. Only poor growth, anorexia and hyperesthesia were observed in the subclinical cases. Biochemical analysis showed significant (p<0.05) hypomagnesemia, hypophosphatemia, hypocalcemia and hyperkalemia in clinical cases compared to control. The AST, ALP, CK and LDH and urea were significantly higher in clinical cases compared to both subclinical and control. However, there was a significant reduction in glucose and parathyroid hormone in the clinical cases. Electrocardiographic examination revealed shorter PR, QT and ST intervals, increased QRS complex amplitude, and peaked T wave in the clinical and the subclinical cases. Ruminal fluid had low Mg, Ca and P in both groups compared to control. However, CSF analysis of tetanic calves showed significant reduction (P< 0.05) in Mg level compared to control but not significantly changed in subclinical cases. Of the 10 clinically affected calves, only 8 calves (80%) responded to therapy and convulsive episodes stop, whereas all subclinical cases were successfully responded to Mg therapy as detected by restoring the normal serum mg level. It was concluded that subclinical hypomagnesemia had a high occurrence in calves 2-4 month of age particularly during the cold seasons. Clinical hypomagnesemia occurs only when Mg level is depressed in the CSF. In addition, ECG was a reliable diagnostic tool for early diagnosis of calf tetany. Treatment in the subclinical stages of hypomagnesemia is recommended before development of the clinical tetanic stages. Keywords: Calves, CSF, ECG, hypomagnesemia, subclinical, treatment