Serum lipopolysaccharide as a diagnostic and prognostic biomarker in Canis familiaris pyometra

Specific sensitive diagnostic markers for early diagnosis of canine pyometra have been widely attempted, but none have proven to be a perfect diagnostic marker for clinical practice. Lipopolysaccharide (LPS) or endotoxin is a cell wall component of gram-negative bacteria, released during bacterial death. The early release, inherent stability, and serotype-specificity of endotoxin suggest its potential as a good candidate for early diagnosis of pyometra. The present study focused on understanding the potential of LPS as a diagnostic and prognostic marker in canine pyometra. The study also tried to establish the correlation between bacterial isolates cultured from the vaginal discharge and endotoxin levels. A total of 12 animals presented to University Veterinary Hospitals with open and closed-cervix pyometra were selected and divided into two groups of six dogs each. Serum LPS concentration (ng/mL) was estimated on various days of observation using ELISA. Mean serum LPS concentration was higher in both groups on the day of presentation, and significantly higher levels were observed in animals with closed-cervix pyometra. Bacteriological examination revealed a predominance of gram-negative organisms in both groups. Hence, it establishes LPS as a better diagnostic marker of canine pyometra. Conversely, a reduction in the levels of LPS on subsequent days of observation confirms its efficacy as a prognostic marker.