To Linda Doran: >One possible explanation is that Espie could have a urinary tract >infection that is resistant to the antibiotics she has been given. >Another suggestion is insulinoma, but her last blood test showed normal >glucose levels (about six months ago, I think). Another suggestion was >the breaking down of red blood cells... Fist off, I'm not familiar with insulinoma resulting in red urine. Certainly, the most common cause of red urine is a urinary tract infection. Since Espie was diagnosed with one three weeks ago, this is still the most likely cause. However, at this point, I think your vet needs to do a culture and sensitivity on the urine and find out what is causing the infection. Urinary tract infections in female ferrets can become serious very quickly, by ascending up the ureters and infecting the kidney. Ferrets appear to be more prone to this than other species. If we haven't gotten a handle on the bladder infection, it could have become worse. I don't want to scare you, but blader infections generally don't cause a lot of systemic signs, such as lethargy - kidney infections do. I think you need to talk with your vet about some more definitive ways of combating Espie's UTI. Other possibilities that may be causing the red blood, or contributing to it would be urinary bladder stones, or neoplasia of the urinary tract (very rare). 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 1433]