Clinical Assessment of a Point‐of‐Care Serum Amyloid A Assay in Foals with Bronchopneumonia

Background Despite the paucity of data available, stall‐side serum amyloid (SAA) assays are commonly used to make diagnostic and treatment decisions in foals with bronchopneumonia. Hypothesis Measurement of SAA concentrations can accurately differentiate pneumonic from healthy foals. Animals Fifty‐four pneumonic foals between 3 weeks and 5 months of age were compared to 44 healthy controls. In addition, 47 foals on a farm endemic for R. equi infections were studied. Methods Serum samples were collected from pneumonic foals at hospital admission. Foals were categorized as having pneumonia caused by R. equi or by other microorganisms based on culture of a tracheobronchial aspirate. In addition, serum samples were obtained at 2‐week intervals from foals born at a farm endemic for R. equi. SAA concentrations were measured by a point‐of‐care assay. Diagnostic performance of SAA was assessed by use of receiver operating characteristic curves. Results Concentrations of SAA in foals with bronchopneumonia were significantly (P < 0.001) higher than those of healthy foals, but 15 of 54 pneumonic foals (28%) had SAA concentrations