A post-mortem study on the prevalence of peripheral dental caries in Scottish horses

Evaluating the Role of Inorganic Elements of Camelus Dromedarius Saliva in Protecting Enamel Against Tooth Surface Loss

The aim of this study was to provide insight into the role of camel's saliva in protecting enamel against erosion and to evaluate the levels of salivary sodium, potassium, calcium, and phosphate ions among 2 groups of camels, those with low-grade tooth surface loss and those with high-grade tooth surface loss. Twenty-eight healthy camels, 5 males and 23 females, aged 20 months to 10 years, were divided into 2 groups. Group I comprise camels with "low-grade tooth surface loss" and Group 2 with "high-grade tooth surface loss." Unstimulated saliva was collected by a draining method. The samples were then analyzed for sodium, potassium, calcium, and phosphate concentrations using automated chemistry analysis. Data were then statistically analyzed using the unpaired Student's t-test and Pearson correlation coefficient test. The study found the salivary calcium and phosphate concentrations were significantly lower in the "high-grade" erosion group, in comparison with the other group (P < .0001 and P  =  .0257, respectively). The results also revealed that the more extensive the tooth surface loss, the more carious lesions the subject had (P  =  .023), and that caries are more common in the anterior teeth, particularly the incisors. The authors conclude that alterations in inorganic elements of saliva, particularly the calcium and phosphate ions, play a major role in the development of resistance to tooth surface loss. This work may represent a direction for future research to develop custom-made preventive supplements, which can protect camelid teeth against tooth surface loss.

Bacterial Periodontitis in Horses: An Epidemiological Study in Southern Italy

Equine periodontal disease (EPD) is a painful oral inflammatory syndrome characterized by multifactorial pathogenesis. Although it is well known that bacterial proliferation and consequent gingivitis are caused by the decomposition process of food residues, in hypsodont species, the pathogenetic role and the different bacterial species involved in the progression of EPD must be fully clarified. This study aimed to investigate the association of bacteria, including the complex red bacteria (RCB), with EPD, and to evaluate possible EPD risk factors. Bacterial species, including Treponema denticola, Tannerella forsythia, Porphyromonas gingivalis (belonging to the RCB), Fusobacterium nucleatum, Veilonella parvula, and Prevotella intermedia, were investigated in 125 oral swabs from healthy and EPD-affected horses using real-time multiplex PCR. Subsequently, possible risk factors (i.e., age, gender, and breed of the animals and type of feed used) were evaluated using univariate and multivariate analyses. Tannerella spp. and Treponema spp. were detected in a significantly higher proportion of horses affected by EPD than in healthy animals, although pathogens belonging to RCB were detected in low number of horses. At the same time, none of the investigated pathogens was significantly associated with a particular stage of disease severity. Horses aged older than 20 years were at higher risk of EPD. The high rate of coinfection, statistically associated with EPD, supports the hypothesis that EPD is a complex syndrome characterized by the possible simultaneous involvement of several pathogens and an increased risk depending on the animal's age. Constant oral hygiene is the best prevention to prevent and treat the disease, especially in old animals.

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.

A microbiome analysis of equine peripheral dental caries using next generation sequencing

BACKGROUND

Although, peripheral caries (PC) affects almost half of UK horses, no comprehensive microbiological study has been performed on this disorder. As a high proportion of oral bacteria cannot be conventionally cultured, molecular microbiological techniques such as Next Generation Sequencing are required to examine the complex oral bacteria community.

OBJECTIVES

To identify the microbiota involved in equine PC, including comparing microbiota at the more commonly and severely affected three caudal cheek teeth with the less commonly affected three rostral cheek teeth.

STUDY DESIGN AND METHODS

Equine dental plaque samples were collected from the palatal aspects of cheek teeth of 63 horses. DNA was isolated and amplified using PCR, targeting the V4 region of the 16S rRNA gene and Next Generation Sequencing of these gene amplicons was performed. The acquired data were processed and analysed using Mothur and R.

RESULTS

Streptococcus species was the genus most commonly associated with equine PC, whereas Gemella species was the genus most associated with the control group. In a further analysis where the rostral and caudal cheek teeth were compared with each other and with the control group. Veillonella species was the most commonly associated genus with PC of the rostral cheek teeth, Streptococcus species was the most associated genus with the caudal cheek teeth, and Corynebacterium with the control group.

MAIN LIMITATIONS

Some bacteria can have multiple heterogeneous copies of the 16S rRNA gene, which can affect the estimation of their relative abundance.

CONCLUSIONS

Similar to caries studies in other species, acidogenic and aciduric microorganisms including Streptococcus species were found to be associated with equine peripheral caries.

Prevalence and analysis of equine periodontal disease, diastemata and peripheral caries in a first-opinion horse population in the UK

Equine dental disease remains a widespread affliction in domestic horses, with the potential to cause significant welfare problems. This retrospective study aimed to increase understanding of this aspect of equine health by examining dental records of 932 horses, taken from a 1-year period of first-opinion practice in south-western England and southern Wales. Three grossly-identifiable dental diseases were analysed: equine periodontal disease, diastemata and peripheral caries. The prevalence of active periodontal disease, diastemata and peripheral caries were 13.9%, 8.7% and 8.2%, respectively. Periodontal disease was more common in the mandibular than maxillary arcades (P<0.001) and in the premolar (06-08) than molar (09-11) cheek teeth (P<0.001). Diastemata were also observed more frequently in the mandibular than the maxillary arcades (P<0.001) and in premolar than molar cheek teeth (P<0.001). Peripheral caries were significantly more common in molar than premolar cheek teeth (P<0.001). A positive association was demonstrated between periodontal disease and diastemata (Exp(B)=4.22; P<0.001). Increasing age was a significant risk factor for periodontal disease (P<0.001) and diastemata (P<0.001). Sex was not conclusively established as a risk factor for any dental disease.