Does the Horse Bit Fit?

Have you ever opened your horse’s lips and had a look inside his mouth? Have you also done this with the bit in place?

Have you had his mouth width measured by the dentist, or by yourself?

If you haven’t then you are just assuming your bit fits your horse, you cannot actually know.

The way bits are often displayed in the sad-dlery, or even marked by the manufacturer, is very misleading.

To categorize them as Pony, Cob and Horse leads the owner to assume that if they have a horse over 15hh then it will need a horse-sized bit, usually 5″ wide. This is incorrect!

Dr Hilary Clayton, holder of the Mary Anne McPhail Dressage Chair in Equine Sports Medi-cine at Michigan State University, conducted a study which found: The results showed no rela-tionship between a horse’s height and the size of his oral cavity. In practical terms, this find-ing indicates that we can-not assume that a large horse should wear a big-ger bit than a smaller horse.

This was brought home to me some time ago when one of our ponies was measured for a 5″ bit!

The simplest way to measure your horse’s mouth width is with a BitFit Measure, this is a simple, inexpensive plastic tool that can be purchased from

However, width is not the only thing you should con-sider, have you ever won-dered about the rule of: 1 or 2 wrinkles in the corners of the lips and your bit is fitted ok? What about horses with very thick, tough lips? How tight does your bit have to be to make them wrinkle? What if your horse has very lim-ited room for the bit, if he has two wrinkles the lips may actually be pushed up against his teeth.

I like to put the bridle on the horse with the bit a little loose and see where he likes to carry it; then adjust the cheekpieces to that height.

Depending on what type of bit you use, it may come in contact with the bars of the horse’s mouth (not all do). This is the area where there is no teeth, some-times this becomes injured from harsh bits or rough handling. If you can run your finger along this sur-face it should feel smooth and flat, if there are any ridges or scarring then the bars have been damaged.

Next consider the size of the size of your horse’s tongue, with the mouth closed the tongue takes up all available space and the bit must displace the tongue, or press into the palate. If your horse al-ready has a large tongue then a bit with a thinner mouthpiece may help him be more comfortable. To check for tongue size lift up the lips, while your horse has his mouth closed, and see if there is any tongue pushing out between the teeth.

The hard palate also var-ies, it is the arch your horse has in his mouth, some horses have quite low palates, again you just need to open the lips at the side and have a look.

Some breeds of horses, like the Connemara and Arabian, are known for having a low palate, if this is the case a bit with a port or a thick mouthpiece is not suitable. mouth .closed, and see if there is any tongue push-ing out between the teeth.

If you have a gelding, it is suggested the wolf or bri-dle teeth should be re-moved, these are also pre-sent in some mares. The wolf teeth are not attached to the jaw and become loose and inflamed easily, especially if a bit is knock-ing against them! Doesn’t that give you the shivers?

A regular dental visit is essential for a comfortable mouth and a good dentist will advise you on the size and types of bit that may suit your horse.

Between the ages of 2 and 5yo your horse should see a dentist twice a year, and per-haps more often if you notice discomfort. This is because he will be losing his baby teeth, known as ‘caps’. For morst mature horses not eating a lot of grain, once a year is often enough.

This information is a very basic guide but if you have ticked all the above as ok, and your horse is not showing any signs of discomfort such as: head tossing, hanging his tongue out, dropping his shoulder on corners, carrying his head high or opening his mouth; then you probably have the right fit for your horse!

Bits do vary in action greatly, some are more suited to different styles of training, the hands holding the reins and the shape of the mouth, than others. This is where an expert can help. I recommend searching out ‘experts’ who will let you have a bit on trial.