To Robert Butler: >I'd like to hear a DVM comment on ferret CNS disease. Boy, I would too. Just kidding. This is a wide open subject, but let me talk for just a paragraph. By far, the most common cause of CNS disease in the ferret is islet cell tumor, or insulinoma. The brain is dependent on glucose for its energy, and cannot utilize fat, like some of the other organs in the body. So, when the blood sugar level is depressed, neurologic disease results because the brain runs out of fuel. The pattern of CNS disease in any one animal is unpredictable - it may show up as seizures, hindlimb weakness, loss of contact with one's surroundings, or other less common manifestations. Probably the second most common cause of CNS disease that I see is bacterial infections. These are usually primarily the result of dissemination of bacteria from another site in body to the meninges, and spread inward from there. Irritability, head tilt, and eventually seizures are the most common signs of bacterial meningitis in ferrets. Another type of CNS disease may be the result of brain tumors - however, brain tumors are exceedingly uncommon. The most common manifestation of a brain tumor is seizures, due to aberrant electrical conductivity in the brain. That's CNS disease in a nutshell - take away insulinoma, and you have an exceedingly rare occurrence. Bruce Williams, DVM, DACVP Chief Pathologist, AccuPath [Posted in FML issue 1452]