Diagnostic Differentiation Between Benign and Malignant Lymphoid and Non-Lymphoid Neoplastic Splenic Diseases in Dogs

The retrospective study investigated hematological and biochemical differences in dogs with neoplastic splenic disease (NSD), comparing malignant versus non-malignant, as well as malignant lymphoid versus malignant non-lymphoid tumors. The research included 20 dogs with splenic disease admitted at the University Veterinary Hospital in Skopje within three years. Each dog underwent clinical examination, abdominal ultrasound, blood, serum, and cytology analysis. Based on cytological findings, dogs were divided into two groups: malignant (M, n=14) and benign (B, n=6) spleen disease. The M group was further divided into malignant lymphoid (ML, n=6) and malignant non-lymphoid (MNL, n=8) subgroups. Data (mean±SEM) was analyzed with Kruskal-Wallis and Mann-Whitney U Test with significance levels set at p<0.05. The M group had significantly higher values than B group for white blood cell (32.08±9.29 and 7.37±0.96x10⁹/L, respectively), monocyte (2.89±1.09 and 0.64±0.12x10⁹/L, respectively), neutrophil counts (17.46±3.80 and 5.39±0.88x10⁹/L, respectively), alanine aminotransferase (82.52±12.49 and 36.89±4.14 IU/L, respectively), and alkaline phosphatase levels (279.16±62.06 and 111.80±15.40 IU/L, respectively). Within the M group, ML subgroup had significantly higher values than MNL for white blood cell (62.80±19.65 and 15.02±3.03x10⁹/L, respectively) and neutrophil counts (29.02±7.86 and 11.04±2.22x10⁹/L, respectively), but lower for alkaline phosphatase (252.80±56.02 and 293.80±93.76 U/L, respectively). Ultrasonographic findings of heterogenous hypoechoic nodules (‘leopard’ pattern), pleomorphic lymphoblasts infiltration, and elevated leucocytes, neutrophils, monocytes, alanine transaminase, and alkaline phosphatase, may aid in differentiating malignant from benign NSD in dogs. Additional to the ultrasonographic and cytology findings, elevated leucocytes, neutrophils, and alkaline phosphatase effectively differentiate lymphoid from non-lymphoid NSD in dogs.