text: On the whole, the lymphoid hyperplasia (in any mammal, I believe) merely indicates that there is being a response to the infectious process, and the speen is choosing to be part of that.\n\nRemember that, at a simplistic level, the spleen is just a whopping huge lymph node.  It's a bit more complex than that, of course, but at the level of analysis needed for this question, that's plenty good enough, I think.