Medi-Dart new plastic wingnut (MDCBWN)

Details

The wingnut is one of two parts on a Medi-Dart syringe that decides whether the needle comes back out of the animal cleanly. Working with the needle and the push rod, it sets how far the needle can go and helps push it clear as the ejector moves ahead once the barrel has emptied. Get the size wrong and the dart either does not seat properly or does not release properly. This is the smaller of the two Medi-Dart offers at 9.5 mm (3/8 in), and it is the one intended for younger cattle up to yearlings. The larger 13 mm (1/2 in) wingnut is the choice for cows and bulls. Most operations running a mixed herd end up keeping both on hand and swapping between them, which takes seconds and is far quicker than arguing with a dart that will not let go. It works with the current #6 needle and with the older #5. Bear in mind that the #6 also needs the half-moon push rod to eject as designed, so a wingnut on its own will not convert an older dart to the newer setup. Being plastic, the wingnut is the part most likely to be lost in the grass or cracked in a toolbox, so it is worth having a spare in the kit. It is reusable rather than a consumable, but it is cheap insurance against a wasted trip. Treatment decisions belong with your veterinarian and the label on what you are administering.