Oral Microbiome in Dogs and Cats: Dysbiosis and the Utility of Antimicrobial Therapy in the Treatment of Periodontal Disease

Oral treatment with catechin isolated from Japanese green tea significantly inhibits the growth of periodontal pathogen Porphyromonas gulae and ameliorates the gingivitis and halitosis caused by periodontal disease in cats and dogs

It has been postulated that 90 % of cats and dogs develop periodontal disease by 1 year of age. Periodontal disease develops because of infection by multiple bacteria, including Porphyromonas gulae (P. gulae) and Porphyromonas gingivalis (P. gingivalis), resulting in severe gingivitis, halitosis, and bone lysis. Because periodontal disease is an irreversible disorder, preventive dentistry in veterinary medicine has become pertinent. This study examined the efficacy of catechin isolated from green tea by focusing on its bactericidal effects against P. gulae and P. gingivalis, inhibition of inflammation, and reduction in halitosis in dogs and cats with periodontal disease. The viability of P. gulae and P. gingivalis was significantly inhibited by catechin in a dose-dependent manner in vitro. P. gulae- and P. gingivalis-associated biofilm formation was also significantly suppressed by catechin, but the effect was not as drastic as the bactericidal effect. Hydrogen sulfide and methyl mercaptan generated by P. gulae and P. gingivalis were significantly decreased by catechin, even after a short exposure. Pro-inflammatory cytokine production and phosphorylation of P-38 and JNK induced by P. gulae were inhibited by catechin treatment in a dose-dependent manner. Treatment with 0.01892 % catechin-contained wet food for 1 month (30-35 days) significantly ameliorated halitosis and P. gulae activity, but had no impact on dental plaque and gingivitis. Our findings indicate that oral treatment with catechin can prevent periodontal diseases in both dogs and cats.

ORAL MICROBIOME OF BENNETT'S (NOTAMACROPUS RUFOGRISEUS) AND YELLOW-FOOTED (PETROGALE XANTHOPUS) ROCK WALLABIES AND THE IMPACT OF INTRAORAL DISEASE

Intraoral disease, including macropod progressive periodontal disease, is one of the leading causes of morbidity and mortality for wallabies under human care. Clinical signs associated with intraoral disease vary, and diagnostic findings can be difficult to interpret without intraoral radiographs or advanced imaging; therefore, this disease process can be challenging to detect in its early stages. Previous studies have investigated the effects of intraoral disease on the normal oral microbiome of various domestic species. Results from these studies demonstrate specific changes to the oral microbiome that have the potential to be used as an early indicator of intraoral disease. The purpose of this study was to evaluate the oral microbiome of 12 Bennett's wallabies (Notamacropus rufogriseus) and 3 yellow-footed rock wallabies (Petrogale xanthopus), using next-generation sequencing, to determine if intraoral disease influences the oral microbiome, as demonstrated in other species. The study identified a total of 295 bacterial species and 388 fungal species from the oral cavity of 15 wallabies. Although not statistically significant, the results of the study suggest an increase in the number of anaerobic bacterial species in sites of disease, including Actinomyces bowdenii, a species from the family Propionibacteriaceae, Peptostreptococcus canis, Fretibacterium sp., and Synergistes jonesii. It also revealed a decrease in microbial diversity in animals with active intraoral disease compared with animals without active disease, as well as at the site of disease compared with the control site. Results from this study support the findings of similar studies assessing the oral microbiome of macropods. Additional studies are warranted to better understand the normal oral microbiome of Bennett's and yellow-footed rock wallabies and the dynamic changes in the microbiome that occur in animals with intraoral disease.

The Cultivable Bacteria Colonizing Canine Vagina During Proestrus and Estrus: A Large-Scale Retrospective Study of Influencing Factors

BACKGROUND

The evaluation of canine vaginal bacteria during proestrus and estrus and the chosen parameters will help to prevent the misuse of antibiotics in veterinary medicine.

METHODS

This study carried out a retrospective analysis to obtain microbiological examination results for vaginal swabs from 696 healthy dogs, all of whom were patients from one clinic. Age, body weight, fur length (long or short hair), the time of sampling of vaginal swabs, the duration of proestrus/estrus, progesterone (P4) concentration (the first and last samples), and bacteriological findings were evaluated.

RESULTS

Only 3.7% (26/696) of the samples were negative for bacteria. The impact of fur length was low. However, the calculation of the odds ratios revealed that the chance for a high-grade growth of Escherichia (E.) coli and Mycoplasma (M.) canis increases with body weight class. The earlier the sampling was performed, the lower the number of high-grade cultures (p < 0.01). The duration between the first and last measurement of progesterone (P4) was positively related to the cultural detection of Pasteurellaceae, Streptococcus spp., and Enterococcus spp. (p < 0.05) and negatively to the cultivation of Mycoplasma spp. (p < 0.01).

CONCLUSIONS

Our findings reflect some likely factors contributing to the variability of the physiological vaginal flora in dogs, which may help interpret cultured bacteriological findings.

Dental Abnormalities in Two Dental-Skeletal-Retinal Anomaly-Positive Cane Corso Dogs: A Case Series

Dental-skeletal-retinal-anomaly (DSRA) is a newly described collagenopathy in Cane Corso dogs. The causative mutation has been linked with splice defects within the melanoma inhibitory activity member 3 (MIA/3) gene that codes for the TANGO1 protein. This case series presents the first dental-related radiographic and histopathological abnormalities in two dogs with genetically confirmed DSRA. The clinical, radiological, and histological features are similar to those reported for MIA3/TANGO1 splice defects previously reported in humans and knockout mice. Common clinical features of these patients include generalized opalescent discoloration of the permanent dentition (intrinsic dyschromia), enamel defects, fractured teeth, vision loss, shortened physical stature, and orthopedic abnormalities that resulted in chronic, early-onset lameness. Intraoral radiography revealed delayed dentin deposition, evidence of endodontic disease, and dental hard tissue loss in both cases. Histopathologic findings for both cases were consistent with dentinogenesis imperfecta (DGI). DSRA exhibits autosomal recessive heritability and commercial diagnostic tests are now available. Clinicians should be aware of the etiopathogenesis, genetic inheritance and associated comorbidities in order to treat and counsel clients on the management of this condition. It is recommended that all breeding individuals be tested, and carriers be sterilized or omitted from the breeding population. This case study describes intraoral diagnoses, treatments, and follow-up of two DSRA-positive dogs.

The Presence of Bacteremia in 13 Dogs Undergoing Oral Surgery Without the Use of Antibiotic Therapy

This study aimed to assess if transient bacteremia developed from dental scaling, root planing (SRP) and dental extraction(s), if the bacteria originated from oral flora, and if the amount of bacteremia produced would warrant the use of pre-, intra-, or post-operative antibiotic therapy in healthy canine patients. Blood cultures were obtained from 13 healthy dogs with chronic periodontal disease that necessitated the extraction of one tooth or multiple teeth. Patients included did not receive any antibiotic therapy for a minimum of 2 weeks prior to their scheduled procedure and did not receive antibiotic therapy intra- or post-operatively. Blood collection occurred at specific time increments to determine the presence of bacteremia and if clearance of the bacteremia occurred post-procedure. The study found transient bacteremia developed at different time increments throughout the dental procedure. At the time of the final sample collection, no bacterial growth was evident in any of the blood cultures. Results of the blood cultures indicated that only four of 13 dogs had evidence of bacterial growth at any one of the time increments; however, by the final collection, there was no bacterial growth suggesting the transient bacteremia had cleared without the use of systemic antimicrobial therapy. The study findings indicate that systemic antibiotic usage is not warranted for severe periodontal disease where an episode of transient bacteremia is produced from SRP and dental extractions in an otherwise healthy patient.

Oral microbiome sequencing revealed the enrichment of Fusobacterium sp., Porphyromonas sp., Campylobacter sp., and Neisseria sp. on the oral malignant fibroma surface of giant panda

Introduction

Microbial community composition is closely associated with host disease onset and progression, underscoring the importance of understanding host-microbiota dynamics in various health contexts.

Methods

In this study, we utilized full-length 16S rRNA gene sequencing to conduct species-level identification of the microorganisms in the oral cavity of a giant panda (Ailuropoda melanoleuca) with oral malignant fibroma.

Results

We observed a significant difference between the microbial community of the tumor side and non-tumor side of the oral cavity of the giant panda, with the latter exhibiting higher microbial diversity. The tumor side was dominated by specific microorganisms, such as Fusobacterium simiae, Porphyromonas sp. feline oral taxon 110, Campylobacter sp. feline oral taxon 100, and Neisseria sp. feline oral taxon 078, that have been reported to be associated with tumorigenic processes and periodontal diseases in other organisms. According to the linear discriminant analysis effect size analysis, more than 9 distinct biomarkers were obtained between the tumor side and non-tumor side samples. Furthermore, the Kyoto Encyclopedia of Genes and Genomes analysis revealed that the oral microbiota of the giant panda was significantly associated with genetic information processing and metabolism, particularly cofactor and vitamin, amino acid, and carbohydrate metabolism. Furthermore, a significant bacterial invasion of epithelial cells was predicted in the tumor side.

Discussion

This study provides crucial insights into the association between oral microbiota and oral tumors in giant pandas and offers potential biomarkers that may guide future health assessments and preventive strategies for captive and aging giant pandas.

Species-level characterization of saliva and dental plaque microbiota reveals putative bacterial and functional biomarkers of periodontal diseases in dogs

Periodontal diseases are among the most common bacterial-related pathologies affecting the oral cavity of dogs. Nevertheless, the canine oral ecosystem and its correlations with oral disease development are still far from being fully characterized. In this study, the species-level taxonomic composition of saliva and dental plaque microbiota of 30 healthy dogs was investigated through a shallow shotgun metagenomics approach. The obtained data allowed not only to define the most abundant and prevalent bacterial species of the oral microbiota in healthy dogs, including members of the genera Corynebacterium and Porphyromonas, but also to identify the presence of distinct compositional motifs in the two oral microniches as well as taxonomical differences between dental plaques collected from anterior and posterior teeth. Subsequently, the salivary and dental plaque microbiota of 18 dogs affected by chronic gingival inflammation and 18 dogs with periodontitis were compared to those obtained from the healthy dogs. This analysis allowed the identification of bacterial and metabolic biomarkers correlated with a specific clinical status, including members of the genera Porphyromonas and Fusobacterium as microbial biomarkers of a healthy and diseased oral status, respectively, and genes predicted to encode for metabolites with anti-inflammatory properties as metabolic biomarkers of a healthy status.

Periodontal Pocket Therapy Using a Class IV Dental Diode Laser in Dogs: A Retrospective Analysis

Class IV dental diode lasers have been introduced as a nonsurgical therapy for periodontal pockets in veterinary and human dentistry. This retrospective case series evaluates the use of Class IV dental diode laser therapy for abnormal periodontal pockets in a specialty veterinary dental practice. A hypothesis that the Class IV diode dental laser is a useful adjuvant modality in canine periodontal pocket therapy in the reduction of clinical pocket depth was made. This article discusses and demonstrates diode laser use in periodontal pocket therapy in a specialty veterinary dental practice and reviews the current literature. Inclusion in this study was limited to client-owned dogs with noted periodontal pocketing on any tooth type between 3 and 6 mm, which were treated with closed root planing (RP/C) and laser therapy who returned in 6 to 7 months for recheck of the pockets from the years 2017 to 2020. Twelve patients met the inclusion criteria. A total of 128 periodontal pockets were included in the study. Each periodontal pocket was a case receiving therapy. The mean periodontal pocket depth before the treatment is measured as 3.35 mm. The mean pocket depth of the periodontal pockets following treatment was 0.59 mm. The mean improvement in periodontal pocket depths after diode laser therapy when considering patient and tooth number using linear mixed-effects modeling was 2.63 mm (95% confidence interval [CI]: 1.81-3.46, P < .0001). No statistically significant results were observed for pocket type, as P values were greater than .05.

Effective Modalities of Periodontitis Induction in Rat Model

Induction of periodontal disease using the rat model is the preferred model for human periodontal disease studies that are related to gene expression, mechanisms of inflammatory regulation, microbial and host responses, resolution, and the healing process. There are 3 methods that are frequently used to induce periodontal disease, which are: ligature application, oral bacterial inoculation, and the lipopolysaccharide injection technique. In the ligature model, sterile non-absorbable sutures or orthodontic wires are widely used to induce local irritation and bacterial plaque accumulation. Secondly, mono and mixed cultures of periodontal bacteria are inoculated orally by gavage or topical application. Lastly, lipopolysaccharide extracted from pathogenic bacteria can be directly injected into the gingival sulcus to induce inflammation and stimulate osteoclastogenesis and alveolar bone loss. Among these methods, ligature application induces inflammation and alveolar bone resorption more promptly compared to other methods. This review will provide an overview of the main induction methods in experimental periodontal disease, with their advantages and disadvantages.