http://www.smartgroups.com/message/readmessage.cfm? gid=1423922&messageid=14865&startid=14867 Yes, the spleen will enlarge with a chronic illness (such as adrenal disease, insulinoma, ulcers, heart disease, etc). In most cases the spleen is compensating for the illness and is making red blood cells (extramedullary hematopoiesis). If the spleen becomes enlarged enough to cause pain, limit activity level, or cause constipation then it is time to remove the spleen. Ferrets do just fine without a spleen, and they do not have an increase in bacterial infections after removal like people do. If your ferret is stable enough for surgery, then it is time to consider removing his spleen. BTW they took my spleen out when I was 3 years old. Hope that helps, Jerry Murray, DVM --- brought to the FML with author's permission by Sukie (not a vet) Ferret Health List co-moderator http://www.smartgroups.com/groups/ferrethealth FHL Archives http://fhl.sonic-weasel.org International Ferret Congress http://www.ferretcongress.org [Posted in FML issue 4955]