animal mouths | Vet In Training

Horse Mouths.

Horse mouth (royalty free)

For the next few weeks, I’ll be writing about different animal mouths. Starting with the horse mouth. Horses grasp food using a combination of the lips, tongue, and teeth. Horses’ lips are extremely tactile when it comes to consuming feed. Feeds are mixed with saliva in the mouth to make a moist bolus that can be easily swallowed. There are three pairs of glands that produce saliva – the parotid, the submaxillary, and the sublingual. Horse saliva contains bicarbonate, which buffers and protects amino acids in their highly acidic stomach. Saliva also contains small amounts of amylase which assist with carbohydrate digestion. The mouth contains 36 – 40 teeth. Wolf teeth are not included as not all horses have them. The horse’s upper jaw is wider than the bottom jaw to allow for a chewing motion that is quite complex. The chewing action of the horse is a sweeping action which incorporates both lateral, forward, backwards, and vertical motions. This allows the feed to be effectively ground and mixed with saliva to initiate the digestive process. The texture of the feeds will dramatically influence the chewing rate (jaw sweeps) and rate of ingestion. An average horse will generally take 60,000 jaw sweeps per day when grazing. This amount will be dramatically reduced when confined to a stable and large amounts of grain are fed. When horses chew fibrous feeds such as hay or pasture it is a long jaw sweep action. This is why horses continually out on pasture rarely develop sharp edges on their teeth. Grains are consumed in a shorter sweep which does not extend past the outer edge of the teeth. When large amounts of grain are given, horses chewing action will be changed and the teeth will not be worn evenly. Hooks or sharp edges will start to form on the outside edge of the teeth. Conclusively, mouths are essential for digestion and a discussion about the digestive system would not be complete without them.