After you have determined what your practice needs are, as you research ultrasound machines available, ask if the machine is capable of supporting the procedures you want and how many transducers you will need to do those procedures. If you start with abdomens but eventually want to do hearts as well, does the machine have cardiac capability or can it be upgraded to cardiac functions when you are ready? Sometimes you just need to buy a cardiac transducer when you are ready. Sometimes you have to buy a new machine that can do hearts and abdomens. Think about your future needs. For shallow depths (like cat or exotic abdomens, equine tendons or repro) you need higher frequency transducers. For deeper depths (like large dog or equine abdomens) you need lower frequency transducers. For most procedures in the small animal abdomen, you want a micro-convex transducer. For shallow structures (pancreas, intestines) a linear transducer could be helpful. For cat hearts you need a higher frequency cardiac transducer. For some large dogs and horses, you need a lower frequency cardiac transducer. Colorflow Doppler is very useful in the abdomen, but it will increase the cost of the machine. For cardiac studies, Colorflow and Spectral Doppler (both Pulsed Wave and Continuous Wave) are necessities and will increase your total cost. I caution you not to buy a machine because it is cheap, but because it will do what you need. For diagnostic purposes in any heart, you MUST HAVE COLORFLOW DOPPLER, PULSED WAVE DOPPLER, AND CONTINUOUS WAVE DOPPLER. Will the machine allow you to easily download patient information and images? Can it do video clips? Can the hardware and software be upgraded? How long is the warranty? If it is an older model, how much longer will the manufacturer support repairs?