Medi-Dart small plastic nut (MDSN)

Details

Take a Medi-Dart syringe apart and the small nut is the piece that ends up on the floor of the truck. It is the nut that clamps the needle onto the barrel, and it does that job under the shock of the shot and the pull of the ejection, which is more than its size suggests. Because it is plastic and it is threaded, it is a part that wears. Cross-thread it once in the dark, or overtighten it trying to chase an air leak that was actually the o-ring, and it will never grip properly again. A nut that is not holding the needle square is a good way to lose a needle in an animal, so it is worth replacing at the first sign of stripped or rounded threads. Do not confuse this with the connecting nut used on the extension setup, which is a different part with a different job. If you are ordering blind, check which one is missing from your syringe before adding it to the cart. It is a reusable part rather than a consumable, but it is small, cheap and easily lost in pasture grass, so most operations keep a spare alongside the o-rings. Do up snug rather than hard, and check it before every session. What you are administering and whether it is appropriate remains a matter for your veterinarian and the product label.