Occurrence and Clinicopathologic Features of Splenic Neoplasia Based on Body Weight: 325 Dogs (2003-2013).

Medical records of 396 dogs undergoing splenectomy for treatment of a splenic mass or nodular disease were reviewed retrospectively. Overall distribution of histopathologic diagnosis and clinicopathologic features were evaluated for 325 dogs that met inclusion criteria. Dogs were dichotomized into two groups based on weight, with the statistically derived cutoff identified as 27.8 kg. Malignancy was diagnosed in 58% of dogs, with no difference between small (55%) and large (61%) dogs (P = .291). Overall, 32% of splenic masses were hemangiosarcoma (HSA), which comprised 25 and 39% of all masses in small and large dogs, respectively. The diagnosis of HSA, non-HSA malignancy, or benign splenic disease was significantly different between the groups (P = .019). Of malignant diagnoses, HSA comprised 46 and 65% of small and large dog splenic neoplasms, respectively (P = .009). In both groups, dogs with HSA were significantly more likely to have preoperative anemia, hemoabdomen, thrombocytopenia, and a blood transfusion, as compared to dogs with non-HSA malignancy or benign lesions. Overall, dogs had similar odds of having a malignant splenic lesion regardless of weight, but dogs ≤27.8 kg were significantly less likely to be diagnosed with HSA.