Real-world diagnostic potential of bacterial biomarkers of canine periodontitis.

Introduction: The objective of this study was to investigate the diagnostic potential of bacterial biomarkers by comparing the performance of molecular detection assays with clinical assessments of dog's oral health performed by veterinarians. Methods: Supragingival and subgingival plaque samples were collected from 127 client-owned dogs, pre-booked for procedures under general anesthesia, visiting veterinary practices in the United States. DNA was extracted and bacterial biomarkers quantified using quantitative polymerase chain reaction. Gingivitis and periodontitis were recorded by a trained clinician using the Weighted Gingivitis Periodontitis Score which involved assessing the buccal surfaces of 18 teeth while under general anesthesia. Intraoral dental radiographs of the left and right mandibular first molar teeth were also obtained. These data were then used to establish the diagnostic performance of the molecular assay to detect periodontitis. Results: An initial conscious, visual oral examination performed by the veterinarian identified 67.7% of dogs as having periodontitis, but examination under general anesthesia indicated a higher proportion (86.6%). Analysis of supragingival plaque samples collected by veterinarians from conscious and unconscious dogs demonstrated the assay had an accuracy of 77.7 to 80.9%, a sensitivity of 77.6 to 81.0%, and a specificity of 80.0%. Discussion: Use of this molecular screening tool in conscious dogs has the potential to improve early periodontal disease detection and support veterinary decision making, ultimately improving the oral health of dogs and consequently their quality of life.

Persistent deciduous teeth: Association of prevalence with breed, breed size and body weight in pure-bred client-owned dogs in the United States.

Dogs use their teeth for a multitude of tasks and, as such, it is vital for their health and wellbeing that their oral health is maintained. Persistent deciduous teeth (PDT), those that fail to fall out at the appropriate time, are associated with malocclusion (misaligned bite), soft tissue trauma and increased risk of periodontal disease. The objective of the current study was to perform a retrospective analysis of veterinary medical data to understand the effect of dog breed size, dog breed and body weight on prevalence of PDT. Medical records collected from almost 3 million dogs visiting a chain of veterinary hospitals across the United States over a 5-year period showed an overall prevalence of 7% for PDT, the data represented 60 breeds with extra-small breeds (<6.5 kg) showing significantly higher prevalence (15%) than all other breed sizes (P < 0.001). Statistical modelling of extra-small, small and medium-small breed sizes showed that those on Wellness Plans or that had not received a dental prophylaxis for at least two years had significantly increased odds of PDT being detected (Odds ratio 2.72-3.2 and 2.17-3.36 respectively, P < 0.0001). Dogs with a below ideal body condition score had a decreased odds of PDT (Odds ratio 0.57-0.89, P < 0.0001) whereas those above ideal had an increased odds (Odds ratio 1.11-1.60, P < 0.0001). The findings from this extensive dataset highlight the importance of regular veterinarian examinations to identify and remove PDT, helping to avoid increasing the risk of associated issues such as periodontal disease and malocclusion.

Association of periodontal disease with breed size, breed, weight, and age in pure-bred client-owned dogs in the United States.

Despite periodontal disease (PD) being amongst the most common diagnoses in primary-care practice, the disease is generally underdiagnosed. However, the millions of clinical records generated by pet hospitals each year provide unique opportunities to generate insights about disease risk across large numbers of dogs. The objective of this study was to undertake a retrospective analysis of medical records to ascertain which sizes and breeds of dog are most frequently diagnosed with PD. Although data collection regarding PD was not consistent, it was assumed that the same inconsistencies in recording periodontal abnormalities were present across the range of bodyweight, breed categories and breeds. Over 3 million medical records across 60 breeds of dogs visiting a chain of veterinary hospitals in the United States collected over a 5-year period were analysed. Statistical analysis of a subset of these records found that extra-small (<6.5 kg) breeds of dog were up to five times more likely to be diagnosed with PD than giant breeds (>25 kg) (P <0.0001). The majority of breeds most frequently diagnosed with PD were in the extra-small, small (6.5-9 kg) and medium-small (9-15 kg) breed size categories. Additional risk factors for PD diagnosis included age, being overweight and time since last scale and polish. Veterinarians should consider targeting client education about dental health, and diagnostic efforts, towards canine patients of the small-breed size categories and those with a higher risk of developing PD (e.g. overweight).

Subgingival microbiota of dogs with healthy gingiva or early periodontal disease from different geographical locations.

BACKGROUND: Periodontal disease is the most common oral disease of dogs worldwide and results from a complex interplay between plaque bacteria, the host and environmental factors. Recent studies have enhanced our understanding of the associations between the plaque microbiota and canine periodontal disease. These studies, however, were limited in their geographical reach. Thus associations between the canine oral microbiota and geographical location were investigated by determining the composition of subgingival plaque samples from 587 dogs residing in the United Kingdom (UK), United States of America (USA), China and Thailand using 454-pyrosequencing. RESULTS: After quality filtering 6,944,757 sequence reads were obtained and clustering of these at ≥98% sequence resulted in 280 operational taxonomic units (OTUs) following exclusion of rare OTUs (present at < 0.05% in all four countries). The subgingival plaque from dog populations located in the UK, USA, China and Thailand had a similar composition although the abundance of certain taxa varied significantly among geographical locations. Exploration of the effect of clinical status and age revealed a marked similarity among the bacteria associated with increased age and those associated with gingivitis: Young dogs and those with no gingivitis were dominated by taxa from the phyla Bacteroidetes and Proteobacteria whereas older dogs and those with moderate gingivitis were dominated by members of the Firmicutes. The plaque microbiota of small breed dogs was found to significantly differ to medium and large breeds and was dominated by species belonging to the Firmicutes. CONCLUSIONS: The bacterial associations with health, gingivitis and periodontitis were conserved across dogs from the UK, USA, China and Thailand. These bacterial signatures of periodontal health and disease have potential as biomarkers for disease detection.

A review of the frequency and impact of periodontal disease in dogs.

Periodontal disease is a frequent problem seen in veterinary practices. Primary-care veterinary practices, where diagnosis of periodontal disease is predominantly based on visual oral assessment of conscious dogs, report an average prevalence of 9.3 to 18.2% within the dog population. Detailed examinations of anaesthetised dogs report much higher prevalence of between 44 and 100%. The prevalence and severity of periodontitis varies between sizes of dogs, breeds and individuals. The lack of robust evaluation of these variances opens the opportunity for a review of the topic. A literature search was therefore undertaken to determine the frequency and extent (severity and oral location) of periodontal disease in the dog population. Both clinical and retrospective data based surveys of veterinary records, show there is an increased likelihood of developing periodontitis as age increases and with bodyweight decreases. The maxillary and mandibular incisors, fourth premolars and first molars are likely to develop the disease first although in some breeds the canines may also be involved. Poor oral care is a significant risk factor for the development of periodontal disease although diet, behaviour, environment and genetics are also likely to play a role. The information provided in this review can be used by veterinarians to improve the effectiveness of their diagnosis, treatments and interventions by focussing their efforts on the sizes, breeds and individuals most at risk. Given the potential link between periodontal disease and systemic health, veterinarians have the opportunity to positively impact the quality of life of a large number of dogs and therefore their owners.

A longitudinal assessment of periodontal health status in 53 Labrador retrievers.

OBJECTIVES: To determine the incidence and rates of progression of gingivitis and periodontitis in Labrador retrievers. MATERIALS AND METHODS: Fifty-three dogs, aged 1·1 to 5·9 years, had their periodontal health assessed every 6 months for up to 2 years. The extent of gingivitis and periodontitis was measured around the whole gingival margin of every tooth under general anaesthesia. RESULTS: All dogs had gingivitis at the initial assessment. The majority (64·2%) of tooth aspects had very mild gingivitis. The palatal/lingual aspect of all tooth types was most likely to show bleeding when probed: 63·0% of these aspects had mild or moderate gingivitis. Over 2 years, 56·6% of dogs developed periodontitis and dogs as young as 1·9 years were affected. There was a significant positive correlation between the proportion of teeth with periodontitis and age. In total, 124 teeth (5·7%) developed periodontitis; 88 (71·0%) of these were incisors. The palatal/lingual aspect of the incisors developed the disease first (2·8% of incisor aspects). CLINICAL SIGNIFICANCE: Periodontitis developed in regions that are difficult to see in conscious dogs implying that detection and treatment of disease requires periodic sedation or anaesthesia.

The molecular biology of appressorium turgor generation by the rice blast fungus Magnaporthe grisea.

The rice blast fungus Magnaporthe grisea develops specialized infection structures known as appressoria, which develop enormous turgor pressure to bring about plant infection. Turgor is generated by accumulation of compatible solutes, including glycerol, which is synthesized in large quantities in the appressorium. Glycogen, trehalose and lipids represent the most abundant storage products in M. grisea conidia. Trehalose and glycogen are rapidly degraded during conidial germination and it is known that trehalose synthesis is required for virulence of the fungus. Lipid bodies are transported to the developing appressoria and degraded at the onset of turgor generation, in a process that is cAMP-dependent. A combined biochemical and genetic approach is being used to dissect the process of turgor generation in the rice blast fungus.