SPLENOMEGALY IN THE DOG (I) : NON-NEOPLASTIC vs NEOPLASTIC CONDITIONS vs PROGNOSIS

	The canine spleen is readily accessible during physical examination through abdominal palpation, radiography, and ultrasonography
	Splenomegaly is a relatively common finding in dogs
	Conventional wisdom implies that nodular lesions in the spleen as a cause of splenomegaly are indicative of haemangiosarcoma, representing a condition that is ultimately fatal; but is this true?

To summarise data from a recent survey which correlated pathological diagnoses of splenic disease with postoperative patient survival in 500 dogs

	Non-neoplastic conditions accounted for 257/500 = 51% of cases
	Nodular splenomegaly Hyperplastic nodules Haematoma Hyperplastic nodules + haematoma Diffuse splenomegaly Congestion/torsion Arterial thrombosis/infarction Myeloid hyperplasia (hypersplenism)	209 42 59 105 48 25 15 2	= 41% of cases = 8% = 12% = 21% = 10% = 5% = 3% = <1% (see leaflet no 6 in this series)
	Neoplastic conditions accounted for 241/500 = 48% of cases
	Benign Haemangioma Other Malignant Haemangiosarcoma Lymphoma Other (sarcomas)	27 17 10 214 122 20 72	= 5% of cases = 3% = 2% = 43% = 24% = 4% = 14%

Postoperative survival time

MEANINGFUL PROGNOSIS DEPENDS ON A DETAILED MACRO AND HISTOLOGICAL EXAMINATION OF THE SPLEEN FOLLOWING SPLENECTOMY

	Overall postsplenectomy survival rate of 52% (255/488) at 6 months
	130/203 = 64% dogs with non-neoplastic lesions survived at least 12 months; in contrast
	8/115 = 7% of dogs with haemangiosarcoma survived beyond 12 months
	All long-term survivals with haemangiosarcomas had single-lesion tumours (as opposed to multiple detectable lesions)
	Dogs with diffuse lymphoma had a mean survival time of 2,8 months
	Dogs with nodular splenic lymphoma survived a mean of 8,4 months

Reference
Spangler WL et al Pathological Factors Affecting Postsplenectomy Survival in Dogs. Jnl Vet Int Med 11:166-171 (1997)