Development of periodontal disease in a single flock of sheep: clinical signs, morphology of subgingival plaque and influence of antimicrobial agents

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.

Mineral contents in bone and liver of sheep with or without periodontitis

ABSTRACT Due to the supposed involvement of minerals in cases of ruminant periodontitis, this study aimed to analyze the concentrations of phosphorus (P) in bone, and cobalt (Co), copper (Co), iron (Fe), zinc (Zn) and selenium (Se) in liver of a cohort of sheep affected or not by periodontitis. From an outbreak of the disease in 2011 in Pará state, Brazil, rib and liver samples were obtained from 22 sheep with periodontitis and seven samples from healthy animals. Based on the concentrations of the different minerals in the tissues, we concluded that there was no relationship between periodontal disease in sheep with any mineral deficiency status. In contrast, most of the minerals in the tissues were above or within the recommended concentrations in bone and liver. Within the various aspects which until now have been studied regarding periodontitis in ruminants, the results obtained here corroborate the fact that periodontal disease in sheep is an infectious disease and it is not a consequence of the deficiency or excess of mineral elements in the diet.

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.

Black-pigmented anaerobic bacteria associated with ovine periodontitis

Periodontitis is a polymicrobial infectious disease that causes occlusion change, tooth loss, difficulty in rumination, and premature culling of animals. This study aimed to detect species of the genera Porphyromonas and Prevotella present in the periodontal pocket of sheep with lesions deeper than 5mm (n=14) and in the gingival sulcus of animals considered periodontally healthy (n=20). The presence of microorganisms was evaluated by polymerase chain reaction (PCR) using specific primers for Porphyromonas asaccharolytica, Porphyromonas endodontalis, Porphyromonas gingivalis, Porphyromonas gulae, Prevotella buccae, Prevotella intermedia, Prevotella loescheii, Prevotella melaninogenica, Prevotella nigrescens, Prevotella oralis, and Prevotella tannerae. Prevalence and risk analysis were performed using Student's t-test and Spearman's correlation. Among the Prevotella and Porphyromonas species detected in the periodontal lesions of sheep, P. melaninogenica (85.7%), P. buccae (64.3%), P. gingivalis (50%), and P. endodontalis (50%) were most prevalent. P. gingivalis (15%) and P. oralis (10%) prevailed in the gingival sulcus. P. gulae and P. tannerae were not detected in the 34 samples studied. Data evaluation by t-test verified that occurrence of P. asaccharolytica, P. endodontalis, P. gingivalis, P. buccae, P. intermedia, P. melalinogenica, and P. nigrescens correlated with sheep periodontitis. The findings of this study will be an important contribution to research on pathogenesis of sheep periodontitis and development of its control measures.

Epidemiological, clinical and pathological aspects of an outbreak of periodontitis in sheep

ABSTRACT: The objective of this study was to describe the epidemiological, clinical and pathological aspects of an outbreak of periodontitis in sheep that occurred on a rural property in Benevides, in the state of Pará, Brazil. The first clinical signs of this disease in the herd - visible nodular swollen mandible - were observed about one month after the sheep began grazing on a recently renovated Panicum maximum cv. Massai pasture; the animals were also supplemented with elephant grass (Pennisetum purpureum). From the 545 adult Santa Ines, Dorper, Texel and crossbred sheep, 20 (3.7%) showed facial bulging, particularly of the mandible. These 20 sheep, which were generally over 36 months of age, had low body condition scores as well as dull and ruffled coats; many of them had loose or missing pre, upper or lower molars, showed the formation of abscesses and fistulas, exhibited pain upon palpation and had difficulty chewing. In the same herd, the prevalence of periodontal lesions at the premolars and molar teeth was evaluated via post-mortem examination of 39 young and 17 adult sheep. In 51.3% (20/39) of adolescents and in 100% of adults, periodontal lesions were found at least at one tooth of the dental arch, with unilateral or bilateral periodontal lesions at the maxillary and mandibular teeth. Histopathological analysis of 13 sheep revealed pyogranulomatous inflammation. The second and third maxillary premolars were the teeth that were most affected in young animals, whereas the third pre-molar and the molars, of the maxilla and mandible, were most often affected in adults. These lesions led to severe bone destruction, alterations in the dental arch, occlusion, tooth loss and periodontal abscesses. The epidemiological and clinic-pathological characteristics of this periodontitis outbreak, described here for the first time in sheep in Brazil, were similar to those for bovine periodontitis (“cara inchada”).

A Model of Spontaneous Periodontitis in the Miniature Goat

BACKGROUND

The pathogenesis and progression of periodontal disease have been extensively studied through the use of animal models. However, no animal model has yet been established that is precisely similar to periodontitis in humans. In the present study, we examined the use of Shiba goats as a model for spontaneous periodontitis.

METHODS

Thirty-four Shiba goats (seven males and 27 females, aged 10 to 98 months) were used. We examined periodontitis in Shiba goats clinically, histopathologically, and microbiologically.

RESULTS

The mean probing depth (PD) of the 68 teeth examined was 2.7 +/- 0.8 mm. The incidences of PD > or =3 and 4 mm were 46.4% and 22.1%, respectively. The incidence of bleeding on probing in 68 sites and in 34 animals was 60.7% and 73.5%, respectively. The formation of vertical alveolar bone defects and downgrowth of gingival epithelial cells were found in the areas of periodontitis. The prevalence of Tannerella forsythensis, Campylobacter rectus, Fusobacterium necrophorum, Fusobacterium nucleatum, and Actinobacillus actinomycetemcomitans in subgingival plaque by polymerase chain reaction was 46.4%, 28.5%, 28.5%, 17.8%, and 3.5%, respectively. These percentages were increased in subgingival plaque from PD > or =3 mm.

CONCLUSIONS

The clinical, histopathological, and microbiological features of spontaneous periodontitis in Shiba goats were somewhat similar to those in human periodontitis. Moreover, there are some advantages of using the Shiba goat; the size of the oral cavity is suitable for periodontal treatment, and handling and housing are relatively easy. Therefore, these results suggest that the Shiba goat is a useful animal model for human periodontitis.

Ovine periodontitis as a potential model for periodontal studies. Cross-sectional analysis of clinical, microbiological, and serum immunological parameters

OBJECTIVES

: To investigate infection and host immunity patterns in sheep with naturally occurring "broken-mouth" periodontitis.

MATERIALS AND METHODS

: Eight periodontally healthy (HS) and eight periodontally diseased ewes (PDS) were selected. Subgingival plaque and sera were collected and examined for evidence of human periodontitis-associated pathogens. Serum IgG titers were measured by ELISA to multiple strains of Porphyromonas gingivalis, Bacteroides forsythus, Dichelobacter nodosus, Actinobacillus actinomycetemcomitans, Prevotella intermedia, and Fusobacterium nucleatum as well as several purified antigens (cysteine proteases, LPS, K, and fimbriae).

RESULTS

: Neither the organism Aa nor antigens to Aa were found in any animal. Most animals were positive for Pg, Bf, and Pi, but DNA probes detected no difference between HS and PDS relative to amounts of pathogens in subgingival plaque. PDS had significantly higher serum IgG titers to all Pg strains, to 50% of Bf strains, to the Pi and Fn strains, and to fimbriae and the two cysteine proteases (p-values ranging from 0.05 to 0.001). Regression analysis demonstrated a significant association between number of teeth lost and serum IgG antibody titers to whole-cell sonicate antigens of P. gingivalis strains (p<0.01) and body weight (p<0.01).

CONCLUSIONS

: The presence of pathogens associated with periodontitis was reflected in differences in serum IgG titers between healthy and diseased sheep. This may have influenced animal body weight and might have systemic health and economic consequences. The data suggest that susceptible and non-susceptible sheep can be identified for periodontal research.