Differential Diagnosis: Splenomegaly in Cats

Following are differential diagnoses for cats presented with splenomegaly.*

• Infiltrative 

  • Lymphoma

  • Mast cell tumor

  • Multiple myeloma 

  • Leukemia

  • Hypereosinophilic syndrome  

• Infectious 

  • Cytauxzoonosis 

  • Histoplasmosis

  • Feline infectious peritonitis 

  • Toxoplasmosis 

  • Ehrlichiosis 

  • Bartonellosis

  • Hemotropic mycoplasmosis

• Congestive

  • Sedation 

  • Right-sided congestive heart failure

  • Splenic vein thrombosis

  • Portal hypertension

• Reactive/hyperplastic changes (often cause focal enlargement)

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

  • Nodular hyperplasia 

    • Splenic

    • Complex

    • Lymphoid 

• Focal enlargement due to neoplasia (eg, hemangiosarcoma)

*Splenomegaly refers to diffuse enlargement unless otherwise noted.