can you purchase b12 injections CYANOCOBALAMIN Vitamin Injectable Solution for Horses, 5000-mcg, 100-mL - Easy Refills loss of appetite Vitamin B12 Injection - 10mL

You can certainly combine the shots in the same syringe, but I do not recommend it (unless you are an expert), because if you get an air bubble in the syringe, as you extract the liquid from the vial, you will need to slowly return the liquid into the vial and re-extract it again till theres no bubbles

Dogs/Cats - 0.25 to 0.5 mL

When synthetic vitamin B12 is added to fortified foods and dietary supplements, it is already in free form and, thus, does not require this separation step

High-dose injectable Cyanocobalamin, used for treating severe deficiencies like pernicious anemia, typically requires a prescription from a doctor