Abstract
BACKGROUND: In hospitalized foals, limited data are available on the utility of sequential measurement of SAA concentrations and the value of these data in a clinical setting. HYPOTHESIS/OBJECTIVES: To determine serum amyloid A (SAA) concentrations in ill neonatal foals at multiple timepoints during hospitalization, and to evaluate a potential association with systemic inflammatory response syndrome (SIRS) status, blood culture (BC) result, and survival. ANIMALS: Hospitalized ill foals (n = 90, ≤ 14 days). METHODS: In this retrospective study, foals were classified based on SIRS criteria: "SIRS" or "NonSIRS," BC results, and survival. Serum amyloid A concentrations on admission (ADM), day 1 (D1) and day 2 (D2) were compared within and between groups, using nonparametric tests. Results are presented as median (IQR) (effect size; 95% CI). RESULTS: Serum amyloid A concentrations were higher in SIRS than in NonSIRS foals both on ADM (401 mg/L (99; 855) vs 67 mg/L (23; 685), [ES 129, 95% CI, 15-385]), and on D1 (836 mg/L (616; 1240) vs 212 mg/L (69; 890), [ES 501, 95% CI, 121-724]). On D2, but not on ADM, foals with a positive BC had higher SAA (1244 mg/L (757; 2004)) than BC negative foals (153 mg/L (57; 695), [ES 1002; 95% CI, 282-1418]). On D1, but not on ADM, SAA was higher in non-survivors (729 mg/L (469; 1347) than in survivors (323 mg/L (75; 889), [ES 373; 95% CI, 28-651]). CONCLUSIONS AND CLINICAL IMPORTANCE: Serum amyloid A measurements on D1 and D2 of hospitalization likely reflect both the severity of disease and response to initial treatment. Repeated SAA measurements during hospitalization can aid clinicians in determining severity of disease and can be useful as a prognosticator in ill neonatal foals.