Serum amyloid A concentration in healthy periparturient mares and mares with ascending placentitis.
Authors: Coutinho da Silva M A, Canisso I F, MacPherson M L, Johnson A E M, Divers T J
Journal: Equine veterinary journal
Summary
# Editorial Summary: Serum Amyloid A as a Diagnostic Marker in Equine Placentitis Ascending placentitis remains a significant cause of pregnancy loss in mares, yet early detection remains challenging. This 2013 study investigated whether serum amyloid A (SAA)—an acute-phase protein—could serve as a diagnostic and prognostic biomarker by characterising its normal profile during late gestation and peripartum, then comparing concentrations in healthy mares with those experimentally infected with *Streptococcus zooepidemicus*. Baseline SAA remained consistently low (3.2–8.1 mg/l) throughout late pregnancy, rising significantly within 96±56 hours of inoculation in untreated mares before abortion occurred; crucially, therapeutic intervention prevented SAA elevation in 66% of treated mares, with only 1 of 9 subsequently aborting compared to 75% abortion rate in mares with elevated SAA. The authors conclude that SAA concentration has potential clinical utility as both a prognostic indicator and treatment response marker in placentitis cases, offering practitioners an objective biochemical parameter to guide intervention decisions and predict pregnancy viability during the critical window when antimicrobial and anti-inflammatory therapy is most effective.
Read the full abstract on PubMed
Practical Takeaways
- •SAA concentration can serve as a prognostic indicator for ascending placentitis in mares, helping identify at-risk pregnancies early when intervention is most effective
- •Early therapeutic intervention in mares showing SAA elevation may prevent abortion; treatment success correlates with normalization of SAA levels
- •Baseline SAA values during late gestation (3.2-8.1 mg/l) provide a reference range for detecting pathological elevation in periparturient mares
Key Findings
- •Serum amyloid A remained at low concentrations (3.2-8.1 mg/l) during late gestation in healthy mares, with significant increase within 36 h post partum before returning to baseline by 60 h
- •SAA significantly increased within 96 ± 56 h of Streptococcus zooepidemicus inoculation in control mares and remained elevated until abortion
- •Therapy prevented SAA elevation in 66% (6/9) of treated mares; abortion occurred in 75% of mares with increased SAA versus 0% of mares with baseline SAA concentrations
- •Successful treatment either prevented SAA rise or decreased it to baseline, resulting in delivery of live foals