Needles: Which one do I use?
By Dr Jennifer Wickline
Needles come in a variety of different lengths and diameters and are coded by color for ease of reference. Interestingly enough the diameter of a needle is measured as a gauge the same way wire is measured. It is important to remember the larger the gauge the thinner the needle. For example, a 20-gauge needle is actually larger in diameter than a 25-gauge needle.
Selecting the correct needle for the drug to be injected helps it to be administered in a timely manner while also considering the comfort of the horse. It is important to choose the proper needle gauge for the drug to be injected. If you are injecting a thicker substance such as penicillin, a lower gauge needle should be used. A higher gauge needle will be used to inject a less dense drug such as Banamine or Bute.
The most common needle lengths used in equine medicine are 1.0” and 1.5”. One-inch needles are generally used for foals and subcutaneous injections, whereas 1.5” length needles are normally used for adult horses. With regards to needle gauge, the most frequently used needles in veterinary medicine are 18-gauge (kelly green casing), 19-gauge (olive green), 20-gauge (pink), 22-gauge (blue), and 25-gauge (red).
If you have more questions regarding needles when administering medications to your horse, call our office at 972-524-7075.
Equine Veterinary Services