Which needle has the largest diameter?

The needle with the largest diameter is a 14 gauge needle. In the gauge system used for needles, the diameter of the needle decreases as the gauge number increases. Therefore, a 14 gauge needle is wider than an 18 gauge needle, an 16 gauge needle, and a 20 gauge needle. This larger diameter allows for the faster flow of fluids and is typically used in situations where large volumes of fluid need to be delivered quickly or in emergencies where rapid access to the vascular system is required. Understanding this gauge system is crucial in veterinary practices as it impacts the choice of needle for various procedures, from administering vaccinations to performing surgeries.