Some interesting cases this past week all involving old horses having difficulty chewing hay and grain and loosing weight. They were all great examples of pain as it relates to the ability for the tongue to freely move within the mouth.
A review of all the veterinary texts I have offers no information regarding the tongue other than on occasion it can become cut in two. So I will tell you what I know about the tongue.
The tongue as a muscle is equal in importance to the heart and diaphragm. It is part of the swallowing process. The purpose of the tongue is to position the food between the teeth, help in forming a bolus that is the correct shape for swallowing, mix the food with the saliva for lubrication, and finally propel the bolus back to where it is swallowed. Several studies have proven that if food can be swallowed, then a horse can thrive. If efficient swallowing is prevented because the tongue is in pain and a bolus can’t be easily formed, then the horse will loose weight.
The tongue must be free to move throughout the mouth to complete the bolus forming and mixing process. The one thing that consistently prevents this freedom was seen in the 3 old horses I saw. Razor sharp points in horses with low thresholds of pain. After smoothing out the teeth and removing the sources of pain, all three horses within minutes were eating without spilling grain.
But wait….There's more! The tongue has two other important jobs.
The first is to push the teeth which causes the teeth to become more firmly attached to the tooth socket. In older horses where the length of reserve crown (the part of the tooth below the gum) becomes as short or shorter than the part above the gum, an unstimulated tooth becomes loose and starts to wiggle. This allows feed and bacteria to invade the socket causing the tooth to eventually fall out. In every old horse that I have found loose teeth in, within 6 months of removing sharp pain causing edges, the teeth become firm within the socket.
The second is to clean the gum - socket junction. Every case of gum disease I have come across in the horse has resolved with first removing pain causing points and allowing the tongue to clean the area. Additionally I add antibiotics and an oral flush with Peroxyl (Colgate).
One more thought on the tongue. In days long ago men shaved using a straight steel blade that was sharpened by "stropping" the blade against a leather strap. The tongue acts like the leather strap stropping the teeth. This action causes two things. It sharpens the edges of the teeth into razors and it wears a trough midway back along the bottom row of teeth. I call this the "dipsie doodle" because I like to have fun. Others describe the resulting formation of higher back bottom teeth as a ramp. This ramp is normal and does not affect the horse on the bit but it should not be confused with a hook.
Have I seen a tongue cut and hanging by a thread? You bet. Razor sharp teeth? Unbelievably! Treatment? Float and give the tongue a safe place to heal plus antibiotics. Outcome? Perfect reattachment.
So get the pain removed from your horse's mouth and improve the dental health of your horses. Float them whether you use a bit or not.