How do you measure a horse for a bit?

To measure a horse for a bit, you must determine the precise width of their mouth from corner to corner and assess their unique oral conformation. The most reliable method is using a marked wooden dowel or a specialized bit-measuring tape placed gently in the mouth where the mouthpiece naturally rests.

Step-by-Step Mouth Measurement

To get an accurate width measurement, find a clean, smooth wooden dowel or a piece of flexible plastic tubing about twelve inches long. Gently slide the dowel into your horse's mouth, resting it in the interdental space on the bars—the gap between the front incisors and the back molars where the bit sits. Ensure the horse is relaxed and holding the dowel quietly. Mark the dowel with a pencil or marker on both sides, directly at the outer corners of the lips where the skin ends. Remove the dowel and measure the distance between those two marks with a standard tape measure. This measurement represents your horse's exact mouth width.

When selecting a bit based on this measurement, you must account for the style of the cheekpiece. For loose ring snaffles, add one-quarter of an inch to your measurement to ensure the rings do not pinch the corners of the lips. For fixed-cheek bits, such as D-rings or full cheeks, the fit should be snugger, sitting relatively flush against the lips without squeezing them. If you are a trainer or rider frequently testing different bit sizes and styles on multiple horses, using the Martin Saddlery Blood Knot Slip Ear Headstall - Harness Leather allows you to swap bits quickly without tools during your fitting sessions.

Evaluating Lip and Tongue Conformation

Measuring the width is only the first step; you must also evaluate the thickness of your horse's tongue and the height of their palate. A horse with a thick, fleshy tongue and a low roof of the mouth will have very little clearance, meaning a thick, heavy jointed bit can cause discomfort and bruising. For these horses, a bit that curvedly drapes over the tongue or features a low port is highly beneficial. The Myler Dee with Hooks Stainless Steel Low Port Comfort Snaffle MB 04 Level 2 - 5" Sweet Iron & Copper Inlay is designed specifically to offer tongue relief and eliminate resistance by distributing pressure evenly across the bars.

If you are competing in dressage and require a legal bit that offers similar ergonomic benefits, the Myler MB 32 Mullen Barrel Dee Snaffle Horse Bit - 5" Mouth Stainless Steel with Copper Inlay, Level 2, 3" Dee, Dressage Legal is an excellent alternative. It allows for independent side movement while keeping a soft, relaxed jaw. Remember, if your horse shows signs of extreme discomfort, head tossing, or bleeding, stop using the bit immediately and consult your veterinarian or a certified equine dentist to rule out underlying dental issues or physical injuries.