The Gingiva of Horses With Pituitary Pars Intermedia Dysfunction: A Macroscopic Anatomical Evaluation

Pituitary pars intermedia dysfunction (PPID) is a common neurodegenerative disease mainly in horses older than 15 years. The domestic equine population is following the same demographic change as that seen in humans; it is aging and veterinarians are asked to attend to geriatric horses more frequently. Common problems seen regularly in older equines are dental disorders and especially periodontal disease. As a systemic and endocrine disease, associated with delayed wound healing and impaired immune function, PPID should be considered before major dental treatment in aged equines is started. Possible negative effects of PPID on epithelial tissues could also affect the periodontium. Therefore, the aim of the present study was to identify gross changes in the gingiva associated with PPID. Fourteen horses with clinical signs of PPID and adenoma in the pituitary pars intermedia and 13 controls showing neither clinical signs nor PPID-associated histological changes in the pituitary gland were included. PPID-affected horses (26.9 ± 0.73 years) were significantly older than controls (20.0 ± 1.24 years). In the PPID-affected group, significantly more often an irregular and bulky appearance of the gingival texture was observed, as well as an irregular shape of the gingival margin. Furthermore, the sulcus gingivalis of cheek teeth frequently was deeper than 1 mm. These findings indicate a possible association between age, soft tissue alterations, and PPID and suggest a potential predisposition of PPID-affected horses for periodontal diseases.

Retrospective case review investigating the effect of replacing oaten hay with a non-cereal hay on equine peripheral caries in 42 cases

BACKGROUND

Equine peripheral caries can cause significant morbidity and can have considerable welfare implications. Recent research suggests that diets with high water soluble carbohydrate (WSC) content are associated with high risk of peripheral caries. Previous work has indicated that the condition may be treatable if the inciting cause is removed and the damaged tooth allowed to erupt out, being replaced by the unaffected tooth previously under the gingival margin.

OBJECTIVES

To see whether the peripheral caries process can be ceased if oaten hay (typically high WSC) is removed from the diet and replaced with a non-cereal hay (typically lower WSC).

STUDY DESIGN

Retrospective blinded longitudinal study.

METHODS

Forty-two cases with peripheral caries that were on oaten hay were asked if they would change the hay type from oaten hay to a non-cereal hay or straw (meadow, Rhodes hay, lucerne hay or barley straw). Photographs were taken at the time and then again at subsequent visits. The photographs were anonymised, randomised and scored by six equine veterinary dentists using the Jackson et al. 'Peripheral Caries Grading System' grading scale.

RESULTS

At follow-up, 69.0% of cases were marked as inactive, compared with 47.6% of cases at baseline (OR: 2.45, 95%CI: 1.12-5.36, P = .02). Significantly lower grades of peripheral caries were observed in the gingival, middle and occlusive third of the molars (triadan 9-11's) at follow-up compared with baseline. However, significant improvements were not observed in the premolars (triadan 6-8's).

MAIN LIMITATIONS

This is a review of clinical records, not a prospective study. As such, other changes in the diet and management were not recorded, and there was no control group.

CONCLUSIONS

Recommending clients change their horse's diet from oaten hay (high WSC) to a typically lower WSC hay was associated with significant improvements in equine peripheral caries located in the molars.

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

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.

A new equine peripheral caries grading system: Are the caries likely active or inactive?

BACKGROUND

Equine peripheral caries can be a significant welfare issue in affected horses. Recent work has shown that complete reversal of the condition may be possible if the primary risk factor can be identified and corrected. Determining whether caries are active (deteriorating) or inactive (improving) is of vital importance when formulating a management and treatment plan. A new grading system is proposed that looks at whether caries are likely active or inactive to assist clinicians deciding whether intervention is required.

OBJECTIVES

To examine the reliability of an alternative grading method for equine peripheral caries.

STUDY DESIGN

Online survey of veterinary surgeons.

METHODS

Reviewers (n = 22) graded images of peripheral caries using three methods: the traditional grading system, a new research grading system and a new clinical grading system. Percentage agreement and Fleiss' kappa were used to examine the participant's agreement of the severity of caries.

RESULTS

All percentage agreements and Fleiss' kappa values were significantly greater than zero (P < .001). The Fleiss' kappa for the new methods were higher (ranging from 0.48 to 0.58), but not significantly different from the traditional method (0.40). There was a high level of consistency in the assessment of caries as either active or inactive with both grading systems reporting over 80% agreement. Feedback on the grading systems was positive with over 90% of reviewers saying they were likely to use the system.

MAIN LIMITATIONS

The use of photographs provided some difficulties with image quality and judging whether the dentin was affected without an occlusal image.

CONCLUSIONS

The new grading system produced a consistent estimate of caries severity and provided high levels of agreement on whether the caries were likely 'active' or 'inactive'. This is likely to be very useful clinically to assist practitioners to determine whether intervention is required.