Dear Russ - A splenic aspirate may give us some valuable information - at least let us know what is going on. Extramedullary hematopoiesis, the cause of splenomegaly in about 95% of cases, is commonly the result of chronic GI inflammation (coronavirus also causes a large number of cases.) The problem with empirically treating the spleen is that they seem to have memory - even if you knock it down, the next time there is any inflammation at all systemically - BOING - it's back to its enlarged size (and maybe more) again. I generally only recommend treating Helicobacter to diminish GI signs - not splenic enlargement. If you want to go after the spleen, then remove it. I have never seen an animal suffer systemic illness as a result of splenectomy. However, I have seen them rupture big spleens. With kindest regards, Bruce Williams [Posted in FML issue 3457]