Bit Fit Tips

You know it's important for your horse's saddle and bridle to fit correctly. But don't forget to make sure his bit fits, too. A bit that's too small can pinch the corners of the mouth, while a bit that's too big can move around too much and clunk against his teeth. Rubbed patches or thickened skin at the corners of the mouth are signs of bad bit fit, but it's better not to wait to see physical evidence that a bit doesn't fit well.

To test whether a bit is the proper size for your horse, you need only an ordinary piece of twine and a ruler or tape measure:

Guide the twine into the horse's mouth and back toward the corners so that it is positioned approximately where the bit would lie.

Pull it taut and use your fingers to grasp it at each corner of the lips.

Remove the twine and use your ruler to measure the length between your fingers.

The general rule is that a properly fitted bit measures a quarter-inch longer than the width of the horse's mouth. You can adjust the cheek pieces of the bridle to make sure that the bit rests properly in the bars of the mouth, creating one or two wrinkles at the corners.

Traditionally, horsemen have used the ‘one wrinkle’ rule to determine if the bit is sitting in the right place in the mouth and fits correctly. One wrinkle at the corner of the horse's mouth meant the bit was sitting in the right place. This isn’t always accurate and doesn't necessarily mean the bit fits or is adjusted properly. The bit should fit comfortably across the bars (the toothless gap between the incisors and molars) of the horse’s jaw, and that may mean there isn't just one wrinkle or any wrinkle at all.

If you fit a jointed bit, like a D-ring or loose ring snaffle, there may be no wrinkle on the lips at all. That doesn't mean the bit doesn't fit. The way the bit looks on the outside may not have anything to do with what is happening the horse's mouth. Take a look inside the horse’s mouth by lifting the lips and notice where the bit is sitting on the bars. It should not be sitting so high or low as to hit the teeth on either side of the bar. Pay attention to the horse’s reaction too. Your horse might tell you by chewing and mouthing the bit, or other behavior, that it’s not comfortable. If the bit isn't positioned in the mouth evenly, the horse could start carrying its head to one side or toss its head. Adjust the bridle so that the bit sits balanced on both sides and sits comfortably in the center of the bars.

In addition to width, the overall shape of a horse's mouth, including the hard palate and the size of his tongue, can influence the size of bit he needs. This means that a thicker bit is not always milder. And, as a horse ages, the contours of his mouth may change, so the bit you use now may not be comfortable for him in 10 years. It's easy to start second-guessing your current bit, but don't worry: If your horse is happy and responsive, chances are, it fits just fine. If you're concerned, you can always ask your veterinarian to evaluate it.

Routine Mouth Care

Make it part of your horses stable management routine to have his teeth checked regularly by a good Equine Dental Technician or Vet. Ask them to show you how to part your horse’s lips and look at his mouth and bars after active work as this will enable you to be aware of bitting problems before they become issues.

Routine Bit Care

For a long life and your horse’s welfare, wash the bit after every use, checking it’s condition and dry it with a clean towel. Store in a dry environment. Keep a close eye on your bridle and look out for stitching, loops, clips or buckles that may be in need of repair.