Serum amyloid A alone or in combination with white blood cell count and fibrinogen is associated with inflammatory disease status in horses undergoing elective anesthesia.

Abstract

Objective: The objective of this study was to assess the clinical utility of common systemic inflammatory markers (WBC count [WBCC], plasma fibrinogen, and serum amyloid A [SAA]) for the detection of disease in patients undergoing general anesthesia.

Methods: A retrospective review of 1,002 surgical case records (February 2021 to June 2023) was performed. Systemically stable equine patients undergoing elective orthopedic and soft tissue procedures and that had WBCC, fibrinogen, and SAA evaluated preoperatively were eligible for inclusion. Disease status (healthy vs disease) was recorded for each case on the basis of the final diagnosis and identified comorbidities. Data were analyzed with univariable and multivariable logistic regression models.

Results: A total of 997 horses met the inclusion criteria. The 3 inflammatory markers (WBCC, fibrinogen, and SAA) were each associated with the presence of clinical disease on univariable analysis. Serum amyloid A alone or in combination with WBCC and/or fibrinogen resulted in the strongest multivariable models with the highest area under the receiver operating characteristic curve.

Conclusions: Results of this study affirm the clinical value of assessing SAA in the equine patient for elective procedures when preanesthetic blood work is performed. Evaluation of SAA is easy to perform on a handheld, stall-side device, emphasizing that patient assessment of this hematologic variable can be performed rapidly and economically in both field and hospital settings.

Clinical relevance: Equine practitioners working in the field or in settings with limited resources should consider assessment of SAA alone or in combination with other conventional systemic inflammatory markers when preanesthetic blood testing is performed.