Neutrophil to lymphocyte ratio as a prognostic biomarker in puppies with acute diarrhea

Objectives To document the neutrophil to lymphocyte ratio (NLR) values in systemic inflammatory response syndrome positive (SIRS+) and negative (SIRS-) puppies presenting with acute diarrhea (AD). To determine whether the calculated canine acute diarrhea severity index (CADSI) score was associated with NLR. Also, to investigate the prognostic value of NLR in puppies with acute diarrhea. Design Retrospective study. Setting University veterinary teaching hospital. Animals A total of 85 puppies (2-6 months old), 70 with AD and 15 healthy controls (CON). Interventions None. Measurements and main results Pertinent history, physical examination findings and results of complete blood count analysis of dogs with AD at the time of admission to the hospital were obtained from medical records. Forty-seven of the dogs with AD were SIRS+ and 23 were SIRS-. Of the puppies with AD, 11 died within 7 days after initiation of treatment, 59 survived. NLR values in dogs with AD were statistically higher (P < 0.001) than the CON group, but there was no difference (P = 0.791) between the two groups in terms of white blood cell (WBC) count. The median NLR of SIRS+ (3.66) dogs was significantly higher than the median NLRs of dogs in the SIRS- (1.88) and CON (1.35) groups. While a strong positive correlation (rho = 0.740; P < 0.001) was found between the CADSI score and NLR in dogs with AD, the relationship between WBC and disease severity was not significant (rho = -0.117; P = 0.336). The area under the receiver-operating characteristic curves for nonsurvival in dogs with AD was 0.710 (P = 0.039) for the NLR and 0.773 (P = 0.008) for the WBC. Conclusions Evaluation of NLR at hospital admission may be a useful marker of disease severity and may have prognostic value in puppies with AD. Further investigations are required to understand the implications of these findings.