A wide variety of dental abnormalities have been described in the horse. It is commonly thought that they interfere with chewing and grinding of food, which may be swallowed without being chewed adequately. It is suggested that this may limit the nutrients that can be released from the food, and may lead to weight loss and digestive problems such as colic and choke.
Dental problems are also blamed for poor performance. Horses with painful mouths may concentrate on the pain rather than the bit cues. Dental abnormalities such as sharp points may ulcerate the cheeks or tongue and may lead to evasion of the bit.
Interest in equine dentistry has undergone a revival in the past decade. Despite that, there is actually little scientific evidence that routine floating is beneficial.
One clinician who has been at the forefront of research into the benefit of routine dental care is Dr James Carmalt. In trials on pregnant mares, he demonstrated that floating increased the rostro-caudal movement of the jaw. However, it had no effect on improving weight gain, food digestibility or fecal particle size.
Perhaps of more interest to horse riders is the effect of floating on performance. In work carried out in Canada, Dr Carmalt and colleagues assessed the benefit of floating on performance in horses undertaking standard dressage tests.
The study compared eleven horses that had not had their teeth floated for at least a year with five horses that had received six-monthly dental care.
The horses performed one of two standard dressage tests approved by the Canadian national equine federation (Equine Canada). A single experienced rider rode all the horses for each test, which was marked by two dressage judges.
After each horse had completed the first test, it was sedated and Dr Carmalt assessed the state of the teeth. Common abnormalities were sharp points on outer edges of upper cheek teeth and inner edges of lower cheek teeth. Many horses also had small hooks on the first upper cheek teeth and ramps on the last lower cheek teeth.
The eleven horses then had their teeth floated using a power grinder. The five horses that had received regular dental care were sedated and examined, but did not have their teeth floated.
Two days later the horses performed the second of the two dressage tests. Neither the rider, nor the judges, knew which horses had had their teeth floated and which had not.
As might be expected, the advanced dressage horses performed significantly better than did those with very little training. But there was no significant difference between the advanced horses and those with some experience.
Analysis of the dressage scores showed that floating the teeth had no effect on performance.
The horses were also given a score according to the rider’s impression of how they went. Interestingly, although the rider did not know which horses had been treated, she correctly identified five treated and two untreated horses. She was unable to decide whether the other horses had been treated or not.
This was only a small study involving 16 horses of different abilities. Dr Carmalt suggests that further studies of horses at different levels and types of competition are needed to investigate the value of floating teeth in performance horses.
For more details see:
The effect of occlusal equilibration on sport horse performance.
JL Carmalt, KP Carmalt, SM Barber
J Vet Dent (2006) 23, 226 - 230.