Feed effects on Equine Peripheral Dental Caries

There has long been thinking that molasses added to feedstuffs, sweet feeds, may contribute to dental problems by causing increase decay. Here two types of oat hay, one with a high soluble carbohydrate (HSC) content, one low (LSC) are compared over time. A trend of increasing dental caries was found in the horses on the HSC content. Those who worsened were switched back to LSC where they improved. It would seem there is a good reason to avoid sweet feeds and lower starch feeds in general.
DrO

A Randomized Controlled Trial Assessing the Effects of Feeding High Water-Soluble Carbohydrate (WSC) Oaten Hay Versus Low WSC Oaten Hay on Equine Peripheral Dental Caries
J Equine Vet Sci. 2021 Mar;98
Authors
Kirsten Jackson 1 , Erin Kelty 2 , Michelle Meylan 3 , Marc Tennant 4
Affiliations

1 International Research Collaborative – Oral Health and Equity, Department of Anatomy, Physiology and Human Biology, The University of Western Australia, Crawley, WA. Electronic address: Kirsten@dentalvet.com.au.
2 School of Population and Global Health, The University of Western Australia, Crawley WA.
3 Equine Nutrition Advisor, Milne Feeds, Welshpool, WA.
4 International Research Collaborative – Oral Health and Equity, Department of Anatomy, Physiology and Human Biology, The University of Western Australia, Crawley, WA.

Abstract

Equine peripheral caries (PC) can cause significant dental pathology and appears to be increasing in prevalence and recognition in many areas [1, 2]. Previous studies have identified risk factors for the condition including the feeding of oaten hay [3]. It was hypothesized that this may be due to the higher water soluble carbohydrate (WSC) or “sugar” content of the hay. A randomized control trial involving 30 horses on three properties was completed. The horses were randomly assigned to two groups: high WSC (H-WSC) or low WSC (L-WSC) oaten hay and were then sedated and intraoral photographs and endoscopy were performed for baseline levels. They were maintained on this assigned hay source for three months when they were again sedated, examined, and photographs and endoscopic videos recorded. Horses with significant PC were then changed to meadow hay (previously shown to be lower risk for PC [3]) for seven months and re-examined to assess for recovery. Images and videos were anonymized and graded for PC, and the PC grades of the teeth before and after intervention were compared using a Fisher exact test. Thirteen horses fed L-WSC hay and 15 fed H-WSC hay completed the study. Of horses fed the H-WSC oaten hay, 60% deteriorated and of horses on L-WSC oaten hay, 53.8% improved in PC grade over the trial, however, the difference was not statistically significant (P = .274). All three horses available for recheck after changing to meadow hay improved.