Differential Diagnosis: Splenomegaly in Dogs

Following are differential diagnoses for dogs presented with splenomegaly.*

• Infiltrative disease

  • Neoplasia 

    • Hemangiosarcoma (may be focal enlargement/mass as opposed to diffuse splenomegaly)

    • Lymphoma

    • Mast cell tumor

    • Plasma cell neoplasia

    • Histiocytic sarcoma (diffuse or focal enlargement) 

    • Other sarcomas (eg, leiomyosarcoma, fibrosarcoma; often focal enlargement) 

    • Leukemia 

  • Amyloidosis 

• Infectious disease 

  • Bacterial

    • Brucellosis

    • Rickettsial (ie, ehrlichiosis, anaplasmosis)

    • Salmonellosis 

    • Tularemia

  • Viral

    • Infectious canine hepatitis

  • Fungal

    • Histoplasmosis

  • Protozoal 

    • Babesiosis

    • Hepatozoonosis

• Reactive/hyperplastic changes (often cause focal enlargement) 

  • Lymphoid hyperplasia

  • Nodular hyperplasia 

    • Splenic

    • Complex

    • Lymphoid 

  • Extramedullary hematopoiesis (eg, bone marrow failure [myelofibrosis, myelophthisis, toxicity, immune-mediated disease, radiation], tissue inflammation or injury, hypoxia, hemolytic anemia, splenic hematoma, splenic thrombosis, lymphoid hyperplasia) 

  • Hematoma 

• Congestion 

  • Anesthesia/sedation

  • Right-sided congestive heart failure

  • Portal hypertension

  • Splenic vein thrombosis 

  • Splenic torsion

*Splenomegaly refers to diffuse enlargement unless otherwise noted.