Hypomagnesæmia in Equine Transit Tetany

Abstract

Pronounced hypomagnesæmia, as well as hypocalcæmia, is shown to be a characteristic feature of “transit tetany” occurring in pasture-reared horses, generally suckling mares, during or after the disturbance of a long railway journey, or of the transfer from free range to confinement. The condition is compared with “grass tetany” of the bovine occurring most commonly after transfer of cows from winter stall conditions to spring pasture, although not restricted to such environmental change and occasionally occurring in breeds at grass all the year round. The symptom complex and biochemical blood picture in the equine is more analogous to atypical “grass tetany” in the bovine than to the typical disorder characterised by comparatively straight hypomagnesæmia, and is easily distinguished from “milk fever” characterised by hypocalcæmia with normal or even slightly elevated serum magnesium.