The Senior Horse

drive to drink and inadequate intake of water is also a risk factor. Difficulty in chewing feed can result in undigested food entering the gut which can also lead to gas or impaction colic.
Digestion is impaired if a horse is unable to grind food properly. Schedule regular dental checkups with your veterinarian to make sure teeth are aligned with no jagged edges and your senior horse has a balanced surface to effectively grind food. If changes in feed are required due to difficulty in chewing be sure to make these changes slowly to allow gut bacteria and enzymes to adapt.
Dental Health 
Extra diligence needs to be paid to dental health in the senior horse. The front teeth continually erupt at an angle that increases as they age. Cases of unbalanced chewing surfaces escalate as the horse ages. Horses wear down their teeth as they chew but that wear is not always even. The development of sharp points in the mouth is much more prevalent in the elderly equine and this can result in ulcerations reluctance to chew food poor digestion and a higher incidence of choke. Severely uneven wear can lead to a condition called wave mouth where at least two molars are higher than the others so that when viewed from the side the grinding surfaces produce a wavelike pattern. Missing or loose teeth can lead to step mouth where one tooth grows longer than the others usually because the corresponding tooth in the opposite jaw is missing or broken and could not wear down its opposite. Step mouth requires regular inspection and care as food can get packed in leading to dental disease abscess or infection.
In very elderly horses the teeth may lose their rough edges and become entirely smooth which results in an inability to grind food. Horses with smooth mouth should be fed highly digestible feeds that are easy to eat such as soaked hay cubes or beet pulp your veterinarian or equine nutritionist will be able to recommend the best course of management.
Annual dental exams are recommended for all horses and should be performed twice a year for elderly horses. Foul odours coming from the mouth nasal discharge loose incisors broken teeth red or inflamed gums quidding chewing then dropping balledup lumps of food weight loss not finishing feed and resistance to the bridle are all reasons to call the vet and have the teeth