FITTING THE JOINTED SNAFFLE BIT (Presented by Dr. Hilary Clayton at the 1998 USDF National Dressage Symposium and re-printed in USDF Connection, June 1999) Last month we looked at the position of the jointed snaffle bit within the horse's mouth as visualized using fluoroscopy (moving X rays). My experiences in watching fluoroscopic videos of different horses wearing snaffle bits of various sizes and adjusted in different ways have led me to some interesting conclusions that I'd like to share with you. Keep in mind though, that each horse is an individual and although the generalizations that follow apply to the majority of horses, there are exceptions to every rule. Bit Size Most horses seem to be most comfortable with a jointed snaffle mouthpiece that is only slightly longer (from ring to ring) than the width of the horse's mouth (from lip to lip). To determine the appropriate bit size, put a bit in the horse's mouth and hold one ring of the bit against the corner of the lips and cheek without indenting them. Gently pull the other bit ring until the two arms of the mouthpiece are aligned. If the horse's lips are pulled inwards, then the bit is too short. On the other hand, if more than ½" of mouthpiece protrudes then the bit is too long. You can measure the excess length and use this to determine the correct length for the mouthpiece. (Note that you can also buy a device designed to measure the width of the horse's mouth). A bit that's too short pulls in the horse's cheeks and squeezes the loose tissues inside the horse's cheek against the premolar teeth, where they are vulnerable to abrasions. This leads to discomfort and resistance. In my experience, though, a bit that's too short is a much less common problem than a bit that's too long. In this context, it's important to realize that the width of a horse's jaw does not necessarily increase in proportion with the height at the withers. Some large warmbloods have surprisingly narrow mouths. Fluoroscopy has shown that the joint hangs lower on the horse's tongue when the bit is too long, which seems to irritate the horse - perhaps because it stimulates the oral reflexes associated with eating and chewing. Another problem is that a longer mouthpiece makes it is easier for the horse to get the bit between his teeth and crunch on it. Fluoroscopic views of a jointed snaffle bit in the horse's mouth. In all pictures the horse is looking to the right. The bit on the left picture is appropriate in terms of its length and adjustment. Note the position of the joint on the horse's tongue (T) and its proximity to the canine teeth (C). The center picture shows the same bit with the cheek pieces 1" longer, and the picture on the right shows a mouthpiece that's 1" too long. In both cases the joint of the bit hangs lower on the horse's tongue (closer to the canine teeth).   Adjustment of the Cheek Pieces After selecting a bit of an appropriate length, the cheek pieces must be adjusted. If the cheek pieces are too long, the bit hangs lower on the tongue and causes the same problems as a bit that's too wide; the horse is likely to fuss with the bit, to play with it using his tongue and to crunch it between his teeth. My guide for 'correct' adjustment is that the bit should be supported by the cheek pieces at all times, especially when the reins are being used. If the cheek pieces become loose when you use the reins or if the bit rings bounce up and down within the cheek pieces, it indicates that they are too long. 'Correct' adjustment usually results in one or two wrinkles in the corners of the lips, which is easily accommodated without discomfort by the looseness of the oral tissues. The Last Word If your horse is unduly fussy with the bit or chews on it excessively, check the fitting of the bit, especially the length of the mouthpiece and the adjustment of the cheek pieces. Of course, the bit is not the only cause of bitting problems, but it's a good place to start in your search for a solution. Figures are reprinted with permission from the Journal of Equine Veterinary Science