Effects of Age and Impending Parturition upon Serum Copper of Thoroughbred Mares

Abstract

During an investigation of the possible relationship between serum copper and the incidence of parturient uterine artery rupture of mares, sera from 475 Thoroughbred mares less than 30 days prepartum were assayed for copper and protein. Serum copper decreased significantly from a predicted mean of 1.70 μg Cu/ml at age 4 years to 1.52 μg/ml at age 20 years. There was a significant increase in serum copper between 30 and zero days prepartum. Mares fatally hemorrhaging from ruptured uterine artery at parturition had significantly lower serum copper levels than the predicted levels for non-hemorrhaging mares of comparable ages, whereas nonfatal cases of apparent uterine artery rupture at parturition had serum copper levels not significantly different from predicted levels for mares of comparable ages.