Rx Vitamins Rx B12 is a highly palatable, bioavailable vitamin B12 supplement for dogs and cats. Each milliliter delivers 250 mcg of cyanocobalamin, making it easy to provide a consistent source of B12. The included graduated dropper helps ensure accurate dosing for pets of different sizes. Available in 120 ml Original and 60 ml Forte formats, it’s a convenient choice for pet parents searching for dog vitamins, cat vitamins, and everyday dog supplements or cat supplements.