Background: this study aimed to identify potential biomarkers for the screening and therapeutic monitoring of sepsis in canine pyometra and correlations with clinical parameters. Samples were collected from a total of 90 dogs with pyometra and 26 healthy female controls. The levels of inflammatory biomarkers and clinical parameters recorded in the dogs with pyometra at presentation were compared with those in the healthy subjects. In addition, consecutive samples from 22 dogs with surgically corrected pyometra and nine healthy controls, were compared before and after ovariohysterectomy.
Results: significant leucocytosis, anaemia, hyperglobulinaemia, hypoalbuminaemia, and elevated activities of the alanine aminotransferase and alkaline phosphatase (ALP) enzymes, were observed in the dogs with pyometra at presentation. Moreover, the concentrations of acute inflammatory proteins of C-reactive protein (CRP) and serum amyloid A (SAA), as well as those of cell-free DNA (cfDNA), were significantly higher in the dogs with pyometra. cfDNA was the most sensitive biomarker for systemic inflammation, based on the receiver operating characteristic curve analysis (area under the curve = 0.959). After surgical removal of the inflamed uterus, leucocyte and red blood cell counts, cholesterol, albumin, globulin levels, and the ALP activity significantly decreased. The levels of inflammatory parameters such as interleukin-6 (IL-6), high-mobility group box 1 (HMGB1), and procalcitonin (PCT) also significantly decreased after surgical treatment.
Conclusions: these findings indicate that cfDNA, CRP, and SAA have the potential to be used as clinical biomarkers for screening canine sepsis, whereas PCT, IL-6, and HMGB1 may be useful biomarkers for the therapeutic monitoring of canine sepsis.