To Steve: > I poured all over the FAQs and didn't find anything on cystic kidneys. So >hear is a question for the Vets out there could you explain how this... Interesting that this question came up - as soon as I find time in my schedule, I was going to put an article on the Path Web page about cystic kidneys, since I've recently gotten some excellent pictures. Cystic kidneys in ferrets may be either congenital (they are born with them), or more commonly, acquired. The vast majority of cysts cause no problems in ferrets, and I see them in around 25% of all ferret autopsies. They are just large empty spaces in the kidney, often causes by scarring around some of the ductowork in the kidney, and obstruction of the plumbing. Although they can reach a large size, the rest of the kidney continues to function normally. Sometimes they get so big that we pick them up on an X-ray. Another way that ferrets can get cystic kidneys may be more dangerous to the ferret. Following a urinary tract infection (remember how I always say to get the urinary tract infections seen quickly?), accumulation of cellular debris and inflammatory cells can obstruct the ureters (the tubes that drain urine from the ikidneys to the bladder) and the kidney can't pass any more urine. As the urine begins to back up, the kidney is damaged due to the pressure, and eventually is destroyed. This is known as hydronephrosis, and means that the kidney is no longer functioning. Then the ferret must live on one kidney. If both are affected, then it can become life-threatening. Finally, a third, very uncommon form of cystic kidneys is a congenital disorder known as polycystic kidneys. This is usually seen in young ferrets, becuase the kidneys do not work properly. In this condition, the kdiney is not put together properly, and the filtration parts (glomeruli) do not connect with the disposal parts (tubules). The result in numerous cysts throughout BOTH kdineys which replace the normal tissues. These animals often die early in life due to lack of functioning renal tissue. Check with your vet and make sure the tissue has been reviewed by a veterinary pathologist so that we know what condition we are dealing with... Bruce Williams, DVM, DACVP Chief Pathologist, AccuPath Dept. of Veterinary Pathology [log in to unmask] Armed Forces Institute of Pathology [log in to unmask] [Posted in FML issue 1452]