The Canadian 2.1 measurement is in mmol(millimols/litre) a measure of molecular weight. To convert to US measurement muliply by 18. So 2.1 mmol = 38 mg/dl(milligrams/decilitre), that is very low and is almost certainly insulinoma. The conversion is different for all parameters so the '18' only pertains to blood glucose. Tony (not a vet), Sugar and Suki. In memory of Sally and Sue. [Posted in FML 5498]