Retrospective evaluation of anemia and erythrocyte morphological anomalies in dogs with lymphoma or inflammatory bowel disease

OBJECTIVE To assess the prevalences of anemia and various RBC anomalies in dogs with lymphoma versus inflammatory bowel disease (IBD) and to evaluate potential relationships between these variables and the severity of lymphoma. DESIGN Retrospective cross-sectional study. ANIMALS 82 client-owned dogs. PROCEDURES Medical records and blood smears were reviewed for dogs in which IBD or lymphoma had been diagnosed between January 1, 2006, and December 31, 2014, and for healthy dogs evaluated during that time frame. Hematologic data were analyzed, and results were compared among groups of healthy dogs, dogs with IBD, and dogs with lymphoma. Results were also compared within the lymphoma group between dogs further grouped on the basis of lymphoma clinical stage, substage, and cell size. RESULTS Prevalence of anemia was significantly higher in dogs with lymphoma (17/32 [53%]) than in dogs with IBD (5/23 [22%]). The total number of different RBC anomalies was significantly higher in dogs with lymphoma than in dogs that were healthy or had IBD. A cutoff of 3 different RBC anomalies/dog enabled differentiation between lymphoma and IBD, with a sensitivity and specificity of 71% and 70%, respectively (area under the fitted curve, 0.7239 +/- 0.0727). The presence of eccentrocytes was the only individual RBC anomaly significantly more common in dogs with lymphoma (8/28 [29%]) versus dogs with IBD (1/23 [4%]). CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that detection of anemia combined with >= 3 RBC morphological anomalies, particularly eccentrocytes, on blood smears should increase the clinical suspicion of lymphoma, compared with IBD, in dogs.