The High Risk Mare

mammary secretion are beneficial for farm managers because these tests indicate when a mare needs to be watched closely for parturition. The use of breeding dates and mammary development are unreliable predictors of parturition in the horse because of the variability 320 to 365 days in normal gestational length. Changes in the composition of the prefoaling mammary secretion are used to determine fetal maturity and readiness for birth. There are many test kits available that detect increases in total calcium ions or calcium and magnesium ions. Calcium ions increase dramatically in the prefoaling mammary secretion within a few days prior to parturition. This increase is used to indicate impending parturition the safe time window for induction of parturition and to predict the outcome in cases of premature delivery. One of the advantages of using these kits is that a specimen can be drawn daily or twice daily so that the mare can be handled and watched closely during this time. This allows managers to detect problems with their pregnant mares that they may otherwise have missed. The kits are better predictors of when the mare is not going to foal than when she is going to foal hence farm managers and owners have a better idea of when a mare should be watched closely. Mares with low levels of calcium are highly unlikely to foal while mares at or above the kits threshold value are ready to foal and likely to foal within 48 hours of first reaching the kits reported threshold level of calcium.  
Prefoaling mammary secretion may also be tested for immunoglobulin content through the use of a colostrometer or a test kit. A mare with poor quality colostrum may have a foal at risk of failure of passive transfer. In one study mares older than 15 years of age were shown to have a tendency to have colostrum with lower specific gravity than younger mares. Foals from dams with poor quality colostrum may be supplemented with colostrum from another mare or tested for systemic immunoglobulin levels after 12 hours. It is preferable to cross match the foals blood against the mares colostrum to remove the risk of neonatal isoerythrolysis NI from an incompatible donor. Neonatal isoerythrolysis is a disease in foals whereby the antibodies in the colostrum recognize and adhere to foals red blood cells. These red blood cellantibody complexes are then destroyed by the foal and