What Size Needle for B12 Injection? Needles What are the Benefits of B12 Injections? VSM Pharmacy Amazon.com : 12 Gauge Veterinary Needles, Cattle Needle Poultry Injection Needles 10 Sticks, Suitable for Pigeons, Chickens, Ducks, Geese, Pigs, Sheep, Horses, And Other Large And Small Animals (12*20mm) : Patio, Lawn & Garden Know Your Needles A Quick Nursing Guide! , Today, lets understand the different types of needles and their clinical purposes , Green Needle (21G) For IM injections like vaccines or