Clinical approach to splenomegaly in dogs and cats

Because of its anatomic and functional features, the spleen may undergo pathologic changes in a wide variety of localized and systemic diseases. This organ is a major target for many pathologic processes because it is located between the portal and systemic circulation. The spleen can be used as a source of diagnostic information that might help to categorize a disease (e.g., as neoplastic, inflammatory, or infectious) or lead to definitive diagnosis, Fine-needle aspiration of the organ is a reliable and safe way to evaluate generalized splenomegaly, even if thrombocytopenia or other coagulopathy is present. Ultrasonography can be an important tool in defining a disease process in the spleen before exploratory laparotomy is performed. This article examines the various disorders that cause splenic abnormalities and discusses the methods of evaluating the spleen. The clinical approach to localized and generalized splenomegaly is summarized.