>he noticed that there were gritty sand like particles in his urine. >so he looked at it under the microscope and it was crystals forming and >blocking his urthea. he said it could be from the food he ate. the >only food i feed all 5 of my ferrets is superior choice from the ferret >store.com. but my other 4 ferrets never had this problem. One of my ferrets, Beuhler, (now deceased, due to cancer) had a chronic problem with crystals in his urine and blockages. He finally had PU surgery done (to bypass the urethra, so he could "pee like a girl"), then he had no more blockages. At the time I was feeding only Totally Ferret. Now I've added some Superior Choice to their diet. None of my other guys have ever had problems with crystals in their urine. So, I wouldn't necessarily fault the food you have been using. We had tried changing Beuhler's diet but it didn't seem to help prevent the crystals from forming. Nancy and critters [Posted in FML issue 3997]