Determination of the relationships between serum amyloid A, serum calprotectin and fecal calprotectin in healthy and infectious diarrheic calves and their diagnostic significances as inflammatory markers

In this study, serum amyloid A (SAA), serum calprotectin (SCalp) and fecal calprotectin (FCalp) levels were investigated in neonatal calves with infectious diarrhea. Total of 70 calves were divided into E. coli, C. parvum, C. parvum + viral, viral and control groups. Clinical parameters were recorded on days 0 and 7, post treatment. On these days, blood and stool samples were also taken. SAA, SCalp and FCalp levels were measured with commercial ELISA kits. Mean SAA levels on day 0 were measured as 0.54 (0.16–2.18) ng/ml and 38.40 (8.28–83.96) ng/ml for the diarrhea and healthy group, respectively (P < 0.001). Statistically significant difference was also obtained between the diarrhea [68.02 ng/ml 46.66–101.67] and control [24.05 ng/ml 11.92–56] groups in terms of SCalp levels on day 0 (P < 0.001). Cut-off value of SCalp to distinguish E. coli originated diarrhea from viral diarrhea was found to be 70.969 ng/ml (Sens: 94%). FCalp levels on day 0 were 93.08 (22.17–122.88) ng/ml and 87.01 ± 3.33 ng/ml in the diarrhea and healthy groups, respectively (P = 0.04). Cut-off concentration of FCalp was found to be 91.804 ng/ml (P = 0.0057). In addition, as a result of the logistic regression analysis, FCalp's ability to identify animals with diarrhea was found to be 6.316 times (P = 0.009) higher. The highest levels of SCalp and FCalp measured on day 0 were found among E. coli group. As a result, the importance of FCalp and SCalp in diagnosing the status of infectious diarrhea in calves for the first time in the veterinary literature is emphasized.