How to Fit a Horse Bit
A bit should not cause any significant pain, bruising or cuts in a horse’s mouth.
To achieve the most effective results from bitting a horse, make sure you have measured your horse’s mouth properly. Also have your horse’s teeth checked periodically. If he shows any signs of mouth discomfort (below), have your vet give him an oral exam right away. (see Bars)
How to Measure for a Horse Bit
Generally speaking, a bit should extend about 1/4″ -3/8″ beyond the horse’s lips on either side of the face. A bit that is too wide can slip and bang. One that is too narrow can pinch when worked and will exert unrelenting pressure on his face.
The average horse takes a 5″ wide bit. Miniatures might take a bit as small as 3″ and warmbloods and drafts go up to a 6″ wide mouth. If you are using a bit that might pinch your horse’s lips, you will want to use bit guards. If that is the case, add 1/2″ to the width of the mouth as you measure to leave room for the guards.
If you find it difficult to measure, use a dowl, place it in your horse’s mouth where you want the bit to sit, and mark either side with a marker. You can also use a sewing tape measure (the soft kind, not a hardware tape measure) the same way.
If you already have a bit that fits, measure it to select a new one.
A colt just starting to wear his bit should be fitted with no wrinkles at the corner of his mouth. It is best if he learns to “carry” the bit first instead of having the headstall hold the bit. Later, when he is comfortable, one wrinkle at the corner of his mouth is fine. Some trainers will even use a two-wrinkle rule. The most important thing is to have the bit fit comfortably in his mouth. The O-ring snaffle on this colt could cause pinching at the corner of the mouth when rein pressure is applied, so be aware of that possibility. A bit guard might be in order for such a bit.
(Also be aware that colts – and some adult horses -still have wolf teeth, which can cause bit discomfort.)(see Horse Teeth)
It is very important to keep your horse’s mouth in top shape. His teeth need to be floated regularly to take the sharp edges off the molars. Hooks on the back teeth can prevent the lower jaw from sliding forward, which will inhibit his ability to relax and yield to the bit.
Some performance horses have their teeth floated specifically for bit comfort and fit. By filing the front four cheek teeth to round them back, you can make more room for the bit and make the horse more responsive. (“bit seat”) (see Horse Teeth)
- Signs of Mouth Discomfort courtesy of Dr Dean Scoggins University of Illinois College of Veterinary Medicine.
- Reluctance to be bridled or unbridled
- Head Tossing
- Gapping (opening the mouth)
- Lolling the Tongue
- Chewing the Bit
- Stiffness in the jaw or neck
- Leaning on the Bridle
- Excessive tail switching
- Tilting the Head
- Dribbling Grain
- Chewing Abnormally
- Reluctance to eat
- Blood-tinged, foul-smelling drool