Hypocalcemia and hypomagnesemia.

The occurrence of hypocalcemia is well documented in clinical veterinary medicine. In this article, we have attempted to provide an overview of the established causes as well as information on more recently recognized etiologies such as the ionized hypocalcemia seen in cats with urethral obstruction and the presence of the disorder in critically ill patient populations. Hypomagnesemia has been identified as the most common electrolyte abnormality in canine and feline critically ill patients. Magnesium depletion and experience with supplementation appear to have most significance in diabetic ketoacidotic patients with the development of associated refractory hypokalemia. (N. Dhupa, BVM, MRCVS, unpublished observations, 1997). Although cardiac arrythmias are associated with hypomagnesemia in human patients, documentation of this association in veterinary patients is lacking. Because hypomagnesemia has been associated with other electrolyte abnormalities in human and veterinary populations, the detection of hypokalemia (particularly if refractory to therapy), hyponatremia, hypophosphatemia, or hypocalcemia should indicate the possibility of coexisting hypomagnesemia.