Dental disease of sheep

Incisor Disorders of Merino Sheep (Ovis aries)

This study documents dental anomalies in 2414 Merino ewe sheep (Ovis aries) from 7 Australian Merino Sire Evaluation Association sites observed during routine husbandry. Teeth were photographed and evaluated using visual scoring protocols to assess plaque accumulation, enamel wear, and other anomalies across all incisors. Plaque scoring revealed a median plaque score of 3 (IQR ± 1) on buccal surfaces and 2 (IQR ± 2) on lingual surfaces, indicating substantial plaque accumulation across incisors. Two cases of geminated incisors and one case of fused central incisors were identified, representing the first documented cases in sheep and expanding existing knowledge of dental anomalies in sheep. Dental wear assessments showed that 13% of 10-month-old ewes and 33% of 20-month-old ewes had significant enamel loss or pulp exposure, with an average of 2 teeth per affected ewe displaying pulp necrosis. Amelogenesis imperfecta was recorded in 5% of the younger and 37% of the older groups. Missing incisors, suggesting early dentition changeover, were observed in 9% of 20-month-old sheep. Localized enamel hypoplasia, potentially resulting from trauma or disruptions during enamel development, was noted in 1% of both age groups. Dental caries was identified in five 20-month-old ewes with permanent incisors. These findings provide a comprehensive overview of the range and prevalence of dental conditions in Merino sheep, including common wear patterns and rare anomalies. Documenting such conditions in sheep contributes valuable information to veterinary dentistry, highlighting the need for further research into incisor health in sheep.

Co-occurrence of periodontal lesions and dental wear in incisor and masticatory teeth in two sheep flocks in Brazil

BACKGROUND

Periodontitis and tooth wear are multifactorial diseases with distinct etiopathogenesis that affect the health, feed efficiency and welfare of sheep.

METHODS

This study evaluated the co-occurrence of tooth wear and periodontal lesions in 129 ewes from two Brazilian flocks, clinically classified the lesions and presence of dental calculus, and identified potential pathogens in the dental biofilm of 63 ewes by polymerase chain reaction.

RESULTS

Of the 129 ewes included in the study, 75 presented periodontal lesions, while all animals presented tooth wear and dental calculus. Of the animals with periodontal lesions, 16.2% had lesions in incisor teeth and 52.7% in masticatory teeth. Regarding excessive tooth wear, 38.6% had severe wear on the incisor teeth and 89.1% on the masticatory teeth. Ewes older than 36 months had a higher frequency of periodontal lesions in incisor teeth (p < 0.001) and a greater amount of dental calculus (p < 0.001), but there was no association between tooth wear and animal age. Fusobacterium nucleatum, Tannerella forsythia and Fusobacterium necrophorum predominated in periodontal lesions.

LIMITATION

This study is limited by the small sample size and lack of diagnostic imaging to assess periodontal disease.

CONCLUSION

The co-occurrence of periodontal lesions and excessive dental wear involving both the incisor and masticatory teeth suggests that although the two diseases have different aetiologies, they likely have common risk factors.

Dysbiosis and Predicted Functions of the Dental Biofilm of Dairy Goats with Periodontitis

Periodontitis is a polymicrobial biofilm-induced inflammatory disease associated with a dysbiotic microbial community and severely affects the health and welfare of animals. However, little is known regarding the dental microbiota associated with this disease in goats. In this study, we used high-throughput sequencing, network analysis, and predicted functions to investigate the microbiota of clinically healthy goats and those with periodontitis and identify possible pathogens and proteins associated with the disease. Dental microbiomes of goats with periodontitis were richer, and network analyses showed that the number of negative interactions was higher in the networks of animals with periodontitis. Based on the interrelationships, Porphyromonas, Fusobacterium, and Prevotella were suggested to play an important role in the dental microbiota associated with goat periodontitis. Protein families linked to translation, cytoplasmatic translation, and rRNA processing were more abundant in the dental microbiota of goats with periodontitis. In conclusion, the dental biofilm microbiota associated with goat periodontitis seems to be dysbiotic and has significant antagonistic interactions, which discriminate healthy animals from diseased animals and highlight the importance of key bacteria. Thus, these novel findings contribute to the evolution of knowledge regarding the etiopathogenesis of goat periodontitis and possibly to the development of periodontitis control measures.

Dental biofilm and its ecological interrelationships in ovine periodontitis

Introduction. Periodontitis, one of the most common oral disorders in sheep, is caused by a mixed and opportunistic microbiota that severely affects the health and welfare of animals. However, little is known about the ecological processes involved and the composition of the microbiota associated with the development of the disease.Hypothesis/Gap Statement. Using high-throughput sequencing of the 16S ribosomal RNA gene and network analysis it would be possible to discriminate the microbiomes of clinically healthy sheep and those with periodontitis and possibly identify the key microorganisms associated with the disease.Aim. The present study aimed to characterise the composition of dental microbiomes and bacterial co-occurrence networks in clinically healthy sheep and animals with periodontitis.Methodology. Dental biofilm samples were collected from ten sheep with periodontitis and ten clinically healthy animals. Bacteria were identified using high-throughput sequencing of the 16S ribosomal RNA gene.Results. The most prevalent genera in the dental microbiota of sheep with periodontitis were Petrimonas, Acinetobacter, Porphyromonas and Aerococcus. In clinically healthy animals, the most significant genera were unclassified Pasteurellaceae, Pseudomonas, and Neisseria. Fusobacterium was found at high prevalence in the microbiomes of both groups. The dental microbiota of sheep in the two clinical conditions presented different profiles and the diversity and richness of bacteria was greater in the diseased animals. Network analyses showed the presence of a large number of antagonistic interactions between bacteria in the dental microbiota of animals with periodontitis, indicating the occurrence of a dysbiotic community. Through the interrelationships, members of the Prevotella genus are likely to be key pathogens, both in the dental microbiota of healthy animals and those with periodontitis. Porphyromonas stood out among the top three nodes with more centrality and the largest number of hubs in the networks of animals with periodontitis.Conclusion. The dental biofilm microbiota associated with ovine periodontitis is dysbiotic and with significant antagonistic interactions, which discriminates healthy animals from diseased animals and highlights the importance of key bacteria, such as Petrimonas, Porphyromonas, Prevotella and Fusobacterium species.

Management of Risk Factors Associated with Chronic Oral Lesions in Sheep

Oral disorders constitute a significant cause of weight loss in sheep. In a study of disorders of the oral cavity of 36,033 sheep from 60 meat sheep flocks in Spain, we looked for management risk factors associated with chronic oral lesions. Mandibular and maxillary disorders were assessed as an external manifestation of oral lesions by palpation, searching for tissue swellings, fistulae, or open wounds. The prevalence of flocks containing sheep with jaw disorders was 98.3%, with an average individual prevalence of 5.5%. The majority of lesions were located in in the mid-region of the mandible, and the most relevant risk factor was increasing age. Use of acidic diets based on silage and inclusion of hard foods, such as maize straw or hay, was associated with the occurrence of jaw inflammation. It was concluded that hard diets containing plant material with edges and sharp areas, plus acidic foods including silage, are more likely to cause lesions of the gingiva, enabling entry of pathogens to the oral mucosa that eventually establish locally in bony tissues, usually as mandibular osteomyelitis. It was also observed that mineral supplementation appears to prevent the occurrence of these lesions.

Dental disease in alpacas. Part 1: Prevalence of dental disorders and their mutual relationships

BACKGROUND

Dental disease is a troublesome health concern in alpacas. Specifically, the occurrence of tooth root abscesses has been described in veterinary literature. Nevertheless, no objective prevalence data are available for dental disorders in alpacas.

HYPOTHESIS/OBJECTIVES

To determine the prevalence of dental disorders in alpaca herds in Belgium and the Netherlands. To study the associations between the different dental disorders encountered in alpacas.

ANIMALS

A total of 228 alpacas (Vicugna pacos) originating from 25 farms.

METHODS

This is a cross-sectional study. Dental disorders were diagnosed by dental examination of sedated animals using a dental mirror or a portable rigid oroscope.

RESULTS

At the animal level, 82% (n = 187) had dental disorders of which 74.6, 41.7, and 3.9% were cheek teeth, incisor disorders, and canine disorders, respectively. At the level of the cheek teeth, diastemata (43.1%) were most common, followed by wear abnormalities (WA; 39.6%) and periodontal disease (PD; 33.3%). A significant association was detected between the presence of diastemata and PD (odds ratio [OR], 13.1; 95% confidence interval [CI], 6.6-27.7; P < .001). Pulp exposure was significantly associated with the presence of diastemata (OR, 11.8; 95% CI, 3.8-51.5; P < .001), PD (OR, 8.2; 95% CI, 3.1-25.3; P < .001) and WA (OR, 2.9; 95% CI, 1.2-7.4; P = .002).

CONCLUSION AND CLINICAL IMPORTANCE

Dental disorders are highly prevalent in alpacas in Belgium and the Netherlands. Several dental disorders in alpacas had significant associations. To prevent the development of advanced stages of dental disease, routine dental examinations are advised to allow early detection and prompt treatment.

Subgingival bacterial microbiota associated with ovine periodontitis

ABSTRACT: Periodontitis is an inflammatory response in a susceptible host caused by complex microbiota, predominantly composed of Gram-negative anaerobic bacteria. Aiming to characterize the subgingival bacterial microbiota associated with ovine periodontitis, polymerase chain reaction (PCR) was performed in subgingival periodontal pocket samples of 14 sheep with severe periodontitis and in subgingival sulcus biofilm of 14 periodontally healthy sheep in search mainly of Gram-negative and Gram-positive microorganisms considered important periodontopathogens. The most prevalent bacteria in the sheep with periodontal lesions were Tannerella forsythia (78.6%), Treponema denticola (78.6%), Fusobacterium nucleatum (64.3%), and Porphyromonas gingivalis (50%), whereas in the healthy sheep, F. nucleatum (42.8%) was the most often detected bacterium. Statistically significant differences were observed for Campylobacter rectus, Enterococcus faecium, Prevotella nigrescens, T. forsythia, and T. denticola (p<0.05) in the sheep with periodontitis in the comparison between groups. Aggregatibacter actinomycetemcomitans, Enterococcus faecalis, and Porphyromonas gulae were not detected in any of the samples analyzed. In conclusion, C. rectus, E. faecium, P. nigrescens, T. forsythia, and T. denticola were associated with severe lesions caused by ovine periodontitis, and F. nucleatum was the most prevalent microorganism in the subgengival sulcus biofilm of healthy sheep.

Morphometric, densitometric and mechanical properties of mandibular deciduous teeth in 5-month-old Polish Merino sheep

Background

Caries, enamel hypoplasia, molar incisor hipomineralization, amylogenesis imperfecta, dentine dysplasia, hypophosphatasia and other dental disorders lead to tooth mineralization disturbances and structural abnormalities, decreasing masticatory organ functions. Dental disorders in sheep can lead to premature slaughter before they have attained final stage of their reproductive life and induce economic loss due to high flock replacement costs. Growth rate, health status and meat quality of sheep depends on tooth properties and quality determining in large extent efficiency of the masticatory apparatus and initial food break up. Considering lack of basic anatomical and physiological data on teeth properties in sheep, the aim of the study was to evaluate morphometric, densitometric and mechanical traits of deciduous mandibular incisor, canine and the second premolar obtained at the slaughter age of 5 months of life.

Results

The obtained results have shown the highest values of weight, total tooth volume, enamel volume and dentine volume in second premolar. Morphometric and mechanical parameters of incisors reached the highest values in first incisor and decreased gradually in second and third incisor, and in canine. Densitometric measurements have not revealed significant differences of the volumetric tooth mineral density in hard dental tissues between the investigated teeth.

Conclusions

In conclusion, proposed methodological approach is noninvasive since the deciduous teeth undergo physiological replacement with permanent teeth. Deciduous teeth can be easy collected for analyses from large animal population and may reflect mineral status and metabolism resulting from postnatal growth and development of the whole flock. In individual cases, evaluation of properties of deciduous teeth may serve for breeding selection and further reproduction of sheep possessing favorable traits of teeth and better masticatory system functions.