The effects of the different type of spleen neoplastic disease on red blood cells (RBCs), mean corpuscular volume (MCV), and platelet count (PLT) are unknown. We examined 88 dogs (n=88) with benign (GB) or malignant (GM) spleen neoplasia and examined variations in RBCs, MCV, and PLT before(M1), 48 hours after(M2), and 8 days after total splenectomy surgery(M3). Overall, between M1 and M2, RBCs decreased by 12.7%, MCV increased by 0.7%, and PLT increased by 74.3%; between M1 and M3, RBCs decreased by 4.11%, MCV increased by 2.04%, and PLT increased by 129.82%. Variations across M1-M3 for GB and GM patients were, respectively, a 7.14% increase and 15.28% decrease in RBCs, 2.12% and 1.87% increases in MCV, and increases of 248.16% and 103.15% in PLT. We concluded that the type of spleen neoplastic disease does not influence in a statistically significant manner the RBC, MCV, and PLT variations in dogs that underwent total splenectomy.