Prevalence and incidence of serum magnesium abnormalities in hospitalized cats

Abstract

Total serum magnesium concentration ([Mg2+]5) was prospectively determined for 57 cats admitted to the intensive care unit (ICU) of the Cornell University Hospital for Animals. Data were collected and analyzed to determine the following: prevalence and incidence of [Mg2+]5 abnormalities, medical disorders associated with altered |Mg2+]5 association of altered [Mg2+]5, with other electrolyte abnormalities, length of hospitalisation for cats with abnormalities of [Mg2+]5 versus those with normal [Mg2+]5, and survival of cats with abnormal [Mg2+]5 versus those with normal [Mg2+]5. The point prevalence of magnesium abnormalities was 26%. the period prevalence was 46%, and the cumulative incidence was 23%. Hypermagnesemia was associated with abnormalities of serum potassium (P = .04) and phosphate (P = .01) concentrations. Abnormalities of [Mg2+], were not associated with abnormal serum concentrations of Na+, Ca2+, or Cl2+ On admission, hypomagnesemia was detected in cats with gastrointestinal, endocrine, and other disorders; hypermagnesemia was detected only in cats with renal disease, obstructive uropathy, or neoplastic disease. The median hospital stay for cats that developed abnormal [Mg2+], after admission was longer than for cats that remained normomagnesemic (5 versus 4 days, respectively; P = .03). Despite the longer hospital stay, the survival of these cats was lower than that of normomagnesemic cats (54 versus 77%: P = .05). When all cats were considered, the survival of cats with abnormal [Mg2+]5 also was decreased compared with normomagnesemic cats (62 versus 81%, P = .05). We conclude that abnormalities of [Mg2+]5 may affect morbidity and mortality of affected cats.