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 outcome or duration of hospitalization. Animals: Four hundred one client-owned dogs presented with CPV. Methods-Retrospective multicenter cohort study. Medical records were reviewed to identify dogs with CPV. Data regarding signalment, complete blood count at admission, duration of hospitalization and outcome were collected. Results: 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 under 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 percentiles) 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 however 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.

Macrophages have been confirmed to play a significant role in the behavior of human lymphomas, albeit no consistent data are so far available in canine lymphomas. The present study characterizes the macrophages present in cases of canine nodal lymphoma and their relationship with the histological grade and the immunophenotype. Samples from the lymph nodes of 25 dogs diagnosed with lymphoma were selected. Immunohistochemistry was used to determine the tumor immunophenotype (CD3 and CD20 antibodies) and macrophage characterization (Iba1, MAC387, CD204, CD163 and iNOS antibodies). Macrophage counting was performed in 10 randomly selected, high-power fields per sample. Generalized linear models with Poisson distribution were used for statistical analysis. A significantly greater number of macrophages (Iba1+) were detected in high-grade and B-cell lymphomas. The highest amount of both M1 (iNOS+) and M2 (CD204+ and CD163+) subtypes were observed in B-cell lymphomas. High-grade lymphomas showed a greater number of CD204+ and CD163+ cells and recently recruited MAC387+ macrophages. The latter were most abundant in T than in B-cell lymphomas. In conclusion, a significant population of macrophages is present in canine lymphomas, which constitute a heterogeneous population that shows variations in the amount and immunohistochemical profile according to the histological grade and immunophenotype.

Background: Listeriosis is a severe foodborne infection caused by Listeria monocytogenes, an important foodborne pathogen of animals and humans. Listeriosis is a rare disease in cats. Objective: To describe the clinical, diagnostic imaging, histological, and microbiological features of L. monocytogenes-associated mesenteric lymphadenitis in a cat. Animals: Listeria monocytogenes-associated mesenteric lymphadenitis was confirmed in a cat by histology and microbiology. Results: Two distinct isolates of L. monocytogenes were cultured from the affected mesenteric lymph node and whole genome sequencing was performed. Conclusion and Clinical Importance: This report should alert veterinary clinicians and microbiologists to the syndrome, which may have implications for health and food safety in animals and humans.