Retrospective investigation of the neutrophil-to-lymphocyte ratio in dogs with pneumonia: 49 cases (2011-2016)

Conway, E. A. , Pizarro Del Valle, C. , Waugh, E. M., French, A. and Ridyard, A. E. (2021) Retrospective investigation of the neutrophil-to-lymphocyte ratio in dogs with pneumonia: 49 cases (2011-2016). Journal of Veterinary Emergency and Critical Care, 31(4), pp. 490-497. (doi: 10.1111/vec.13067) (PMID:33960611)

Abstract

Objective To assess the utility of the neutrophil‐to‐lymphocyte ratio (NLR) in predicting outcome in canine pneumonia compared with routine hematological parameters and systemic inflammatory response syndrome (SIRS) scores. Design Retrospective study. Setting University teaching hospital. Animals Forty‐nine client‐owned dogs. Interventions None Measurements and Main Results Medical records were reviewed to identify dogs with a diagnosis of pneumonia from July 2011 to December 2016. Signalment, clinical findings, laboratory characteristics, and outcome were recorded. Inclusion criteria were a clinical and radiographic diagnosis of pneumonia, plus reference laboratory hematology at diagnosis. Cases that received steroids were excluded. Euthanized dogs were only included in statistical analysis if euthanized solely due to pneumonia severity. The NLR, total WBC count, neutrophil count, lymphocyte count, band neutrophil percent of total WBC count (%‐bands), and percentage of cases diagnosed with SIRS were compared between survivors and nonsurvivors. Receiver operating characteristic curves were generated to identify optimal sensitivity and specificity cutoffs for nonsurvival to discharge. Two hundred records were retrieved; 49 cases fulfilled the inclusion criteria. Of these, 33 (67%) survived to discharge. The NLR did not differ significantly between the survivors and nonsurvivors, nor did total WBC count or neutrophil count. Survivors had a significantly lower %‐bands than nonsurvivors (P < 0.001) and higher lymphocyte count (P = 0.004). The mortality rate did not differ significantly between dogs with and without SIRS. Receiver operating characteristic analysis identified a %‐bands cutoff of 2.5% or higher had an 83% sensitivity and 79% specificity for nonsurvival. Conclusions Unlike in human medicine, neither NLR nor SIRS scores predicted outcome in this cohort of dogs with pneumonia. However, survivors had a lower %‐bands and higher lymphocyte count than nonsurvivors, which may be helpful prognostically in clinical cases.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Conway, Dr Elizabeth and Ridyard, Ms Alison and French, Professor Anne and Pizarro Del Valle, Dr Carlos and Waugh, Ms Elspeth
• Authors: Conway, E. A., Pizarro Del Valle, C., Waugh, E. M., French, A., and Ridyard, A. E.
• College/School: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: Journal of Veterinary Emergency and Critical Care
• Publisher: Wiley
• ISSN: 1479-3261
• ISSN (Online): 1476-4431
• Published Online: 07 May 2021
• Copyright Holders: Copyright © 2021 The Authors
• First Published: First published in Journal of Veterinary Emergency and Critical Care 31(4): 490-497
• Publisher Policy: Reproduced under a Creative Commons licence