Evaluation of red blood cell distribution width, neutrophil-to-lymphocyte ratio, and other hematologic parameters in canine acute pancreatitis

Abstract

Objective: To determine if RBC distribution width (RDW), neutrophil-to-lymphocyte ratio (NLR), and other hematological parameters are associated with increased odds of in-hospital mortality, increased length of hospitalization (LOH), or disease severity as measured by the Canine Acute Pancreatitis Severity (CAPS) score in dogs with acute pancreatitis (AP).

Design: Retrospective, multicenter study from January 2016 to August 2020.

Setting: Four private emergency and specialty referral centers.

Animals: On initial case search, 118 client-owned dogs were identified with a clinical diagnosis of AP. Out of these cases, 114 dogs met inclusion criteria, defined as sudden onset of ≥2 compatible clinic signs (lethargy, anorexia, vomiting, or abdominal pain), a specific canine pancreatic lipase concentration >400 μg/L, hospital admission, as well as CBC and serum biochemistry run within 48 hours of initial hospitalization. Disease severity was calculated and measured using the CAPS score, in addition to LOH and in-hospital mortality.

Interventions: None.

Measurements and main results: Clinical endpoints were in-hospital mortality, LOH, and disease severity, as evaluated by the CAPS score. Overall in-hospital mortality was 36.8%. NLR was significantly associated with survival, with a higher percentage being associated with an increased likelihood of nonsurvival (odds ratio: 1.1, 95% confidence interval: 1.0-1.2; P = 0.006, adjusted P = 0.04). Increased NLR was found to be significantly associated with a longer LOH based on the unadjusted P-value (P = 0.02) but was not statistically significant based on a P-value adjusted for multiple comparisons (P = 0.12). No significant associations were noted when RDW, platelet-to-lymphocyte ratio, WBC count, mean platelet volume, RDW-to-platelet ratio, or RDW-to-total serum calcium ratio was evaluated against outcome measures.

Conclusions: This study retrospectively evaluated the prognostic utility of several readily available hematological parameters in dogs hospitalized for AP. Dogs with an increased NLR may have a higher risk of in-hospital mortality and increased LOH, although future prospective studies are necessary to confirm these findings.

Keywords: RBC distribution width; acute pancreatitis; canine; hospital admission; neutrophil-to-lymphocyte ratio.