Retrospective evaluation of hematological ratios in canine parvovirosis: 401 cases

Background: The utility of neutrophil-to-lymphocyte ratio (NLR), platelet to-lymphocyte ratio (PLR) and monocyte-to-lymphocyte ratio (MLR) as prognostic indicators has not been investigated in canine parvovirosis (CPV). Hypothesis: To evaluate whether these hematological ratios obtained at hospital admission in CPV are associated with out-come or duration of hospitalization. Animals.: Four hundred one client-owned dogs presented with CPV. Methods- Retrospective multicenter cohort study. Medical rec-ords were reviewed to identify dogs with CPV. Data regarding signalment, complete blood count at admission, duration of hospitalization and outcome were collected. Re-sults: Of the 401 dogs included in the study, 336 (83.8%) survived to discharge. The median (25th and 75th percentiles) PLR in nonsurvivors (336.56 [159.84-635.77]) was significantly higher than in survivors (217.65 [117.67-389.65]) (P = .003). The area un-der the receiver-operating characteristic curve for nonsurvival was 0.615 (95% CI [0.593-0.691], P = .003). A cut off of 700 showed a 21.5% sensitivity and 90% specificity for nonsurvival. No association was observed between hospitalization duration and either hematological ratios or total WBC counts. The median (25th and 75th percen-tiles) lymphocyte count was below reference interval in all dogs and was significantly lower in the dogs which died (0.82 _ 109/L [0.5-1.87]) than in survivors (1.27 _ 109/L [0.73-2.22]) (P = .005). The median (25th and 75th percentiles) monocyte count how-ever was lower in survivors (0.38 _ 109/L [0.29-1.59]), than in nonsurvivors (0.73 _ 109/L [0.1-2]) (P = .002). Conclusions: Evaluation of PLR at hospital admission might be a useful marker of disease severity and could have prognostic value in dogs with CPV.

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