I have to disagree that ultrasounding ferrets is worthless. I will not go into a surgery without one. However, I have discovered that there are a number of key issues that must be met before doing the ultrasound: First, the ultrasound operater should be extensively trained and experienced. Reading ultrasounds takes training and practice. A vet or technician who received training a long time ago, or little training, or does not do ultrasounding frequently, is not likely to be able to interpret results well. Second, the equipment itself must be designed for ferrets. Much ultrasounding equipment does not have high enough resolution to detect the tiny workings of the insides of our ferrets. The probe should be 7.5 MHz or better, 6.5 MHz is the largest piezoelectric probe that should be used on a ferret, because it can only efficiently detect problems that are 3 mm or greater. The better the resolution, the higher the cost of the equipment, but the better the ability to do a good job on ferrets. Ultrasounds built for dogs, cats, and bovines/equines, simply do not have good capability for ferrets. A good computer image recording system is extremely useful for saving images and measuring sizes and changes over time. But also remember that ultrasounds don't work well on fat ferrets, or ferrets that are full of gas from a recent meal. Squirming ferrets certainly don't help at all! When ultrasounds are used correctly as a diagnostic tool, they are of invaluable assistance to the owner and the surgeon. As an owner, I use ultrasound results to determine if I even want a surgery. In one case, a recent rescue was ultrasounded, and the results showed that cancer had spread everywhere; there was nothing to be done. So instead of letting this rescue be sliced open for nothing, he died comfortably at my home a few weeks later. In another case, the ultrasound determined a bilateral problem (right and left tumors). Because the ferret was old, I elected not to do surgery (I would have if it was only a left tumor). On several ferrets on Lysodren treatment, I use ultrasounds to determine the extent of tumor size reduction to control the dosage of the medication. For the surgeon, the ultrasound can tell which side the tumor is on, so the vet is better prepared for surgery; knows exactly what the situation is, and how long the procedure might take. One of my ferrets had a right adrenal with involvement of the vena cava (as seen on ultrasound). The vet knew he would need additional assistance, tools, and time, and went right to the problem. Ultrasounds are not a cure; nor are they definitive diagnostics. I am certainly willing, however, to pay the cost for the health and well-being of my ferrets, as long as the procedure is performed by an experienced person with the right equipment. Erika Matulich and the 13 fuzzballs President, Ferret Lovers' Club of Texas [Posted in FML issue 2192]