Abstract
BACKGROUND: Hypocalcaemia in relation to postpartum diseases is well researched in bovine medicine, with findings extrapolated from this species for clinical evaluation in the canine. In bitches, the association of serum ionized calcium (iCa(2+)) and the incidence of mastitis and metritis, along with clinical hypocalcaemia signs in bitches, has not yet been evaluated. iCa(2+) and dystocia have been previously assessed with mixed conclusions. OBJECTIVES: The purpose of this study was to compare serum iCa(2+) concentrations between bitches that did or did not develop mastitis, metritis or dystocia. A secondary objective was to assess iCa(2+) concentrations throughout the estrous cycle, including pregnancy and lactation. METHODS: An observational cohort study was conducted in a guide dog population, with serum samples collected to measure iCa(2+) concentrations at four different time points (pre-breeding, late gestation, 24 hours postpartum and 10 weeks postpartum) over a 2.5-year sampling timeframe. Cohorts studied included bitches that did and did not develop postpartum diseases. RESULTS: During 82 estrous cycles recorded from a total of 59 bitches, the overall incidence of mastitis, metritis and dystocia in this population was 21%, 15% and 38%, respectively. Differences in iCa(2+) concentrations were not significant for bitches with mastitis, metritis or dystocia at any time point. iCa(2+) concentrations measured at pre-breeding, late gestation, 24 hours postpartum and 10 weeks postpartum were not different between groups. CONCLUSIONS: iCa(2+) concentrations do not appear to be related to the incidence of dystocia, mastitis or metritis, as documented in this study.