An Update on Feline Chronic Gingivostomatitis

Evaluation of Serum Vitamin D and C Concentrations in Cats With Gingivostomatitis

AIM OF STUDY

To investigate serum vitamin C and D concentrations of cats suffering from gingivostomatitis.

MATERIALS AND METHODS

Serum concentrations of vitamins C and D were evaluated in 30 cats of various breeds, including 15 healthy cats and 15 with gingivostomatitis.

RESULTS

Serum vitamin D concentration in the healthy cats (35.36 ± 15.39 ng/mL) was significantly higher than that of the cats with gingivostomatitis (17.54 ± 10.50 ng/mL) (p < 0.05). There was no difference in serum vitamin C concentration between the healthy cats (3.7 ± 0.74 mg/100 mL) and those with gingivostomatitis (3.1 ± 0.72 mg/100 mL) (p < 0.05).

CONCLUSION

The results of this study suggest that cats with gingivostomatitis are predisposed to vitamin D deficiency. Further studies are required to confirm this finding in a larger study sample and to investigate the potential utility of vitamin D supplementation.

Topical indocyanine green antimicrobial photodynamic therapy for refractory feline chronic gingivostomatitis: A case report

Feline chronic gingivostomatitis (FCGS) is a painful and severe inflammatory mucosal disease in cats that presents significant challenges in treatment. This case study describes a novel approach for a cat with FCGS that was unresponsive to antibiotics, non-steroidal anti-inflammatory drugs, and dental extraction. The cat exhibited rapid improvement after undergoing oral indocyanine green (ICG)-mediated antimicrobial photodynamic therapy (aPDT); however, treatment was discontinued due to an episode of anaphylaxis. Subsequent oral aminolevulinic acid (ALA)-mediated aPDT proved ineffective over nine sessions. The cat was then treated with a topical approach using ICG-aPDT. ICG was prepared by dissolving 5 mg of powder in 3 mL of sterile water, which was applied to the oral gingiva, followed by irradiation with an 810 nm diode laser, delivering a total fluence of 16.8 J/cm2 per session through the skin in two divided doses. The cat underwent biweekly aPDT, totaling 13 treatment sessions without any adverse events over four months. Gradual weight gain was observed from the first treatment. During the three-year follow-up, there was no recurrence of FCGS. This case report highlights the potential efficacy of topical ICG-aPDT as a treatment modality for FCGS.

Effect of Dietary Composite Probiotic Supplementation on the Microbiota of Different Oral Sites in Cats

Probiotics demonstrated effectiveness in modulating oral microbiota and improving oral health in humans and rodents. However, its effects and applications on the oral microbiota of cats remain underexplored. Twelve healthy cats were randomly assigned to a control group (CON) and a composite probiotic group (CPG) for a 42-day trial. The CPG diet included additional supplementation of Bifidobacterium animalis subsp. lactis HN019, Lactobacillus acidophilus NCFM, and Lactobacillus casei LC-11, each at approximately 1 × 1010 CFU/kg. On days 0 and 42, microbial samples were collected from the gingiva, tooth surfaces, and tongue of all cats for 16S rRNA gene sequencing. Bacteroidetes, Firmicutes, and Proteobacteria were the dominant phyla across all oral sites. The CPG treatment enriched seven genera, such as Moraxella, Actinomyces, and Frederiksenia in the gingiva. Meanwhile, Bergeyella and Streptococcus were enriched on the tooth surfaces, while Bergeyella, Flavobacterium, and Luteimonas were enriched on the tongue. Furthermore, the composite probiotic effectively suppressed eight genera, such as Bacteroides, Desulfovibrio, and Filifactor in the gingiva of CPG cats, as well as Helcococcus, Lentimicrobium, and Campylobacter on tooth surfaces, and Porphyromonas, Treponema, and Fusibacter on the tongue. These findings suggest that the composite probiotic used in this study modulates the feline oral microbiota by supporting beneficial or commensal bacteria and inhibiting oral pathogens, demonstrating potential to improve oral health in cats.

Epidemiological investigation of feline chronic gingivostomatitis and its relationship with oral microbiota in Xi'an, China

Feline chronic gingivostomatitis (FCGS) is an ulcerative and/or proliferative disease that typically affects the palatoglossal folds. Because of its unknown pathogenesis and long disease course, it is difficult to treat and has a high recurrence rate. Most of the bacteria in the oral microbiota exist in the mouth symbiotically and maintain a dynamic balance, and when the balance is disrupted, they may cause disease. Disturbance of the oral microbiota may play an important role in the development of FCGS. In this study, the medical records of 3109 cats in three general pet hospitals in Xi 'an were collected. Sixty-one cats with FCGS were investigated via questionnaires, routine oral examinations and laboratory examinations. Oral microbiota samples were collected from 16 FCGS-affected cats, and microbial species were identified by 16S rDNA sequencing. The results showed that the incidence of FCGS had no significant correlation with age, sex or breed. However, the incidence of FCGS was associated with immunization, a history of homelessness and multicat rearing environments. The number of neutrophils and the serum amyloid A concentration were increased, and the percentage of cells positive for calicivirus antigen was high in all cases. All the cats had different degrees of dental calculus, and there were problems such as loss of alveolar bone or tooth resorption. Compared with those in healthy cats, the bacterial diversity and the abundance of anaerobic bacteria were significantly increased in cats with FCGS. Porphyromonas, Treponemas and Fusobacterium were abundant in the mouths of the affected cats and may be potential pathogens of FCGS. After tooth extraction, a shift could be seen in the composition of the oral microbiota in cats with FCGS. An isolated bacteria obtained from the mouths of the affected cats was homologous to P. gulae. Both the identified oral microbiota and the isolated strain of the cats with FCGS had high sensitivity to enrofloxacin and low sensitivity to metronidazole. This study provides support to current clinical criteria in diagnosing FCGS and proposes a more suitable antibiotic therapy.

Epidemiological and clinicopathological findings of feline immunodeficiency virus and feline leukemia virus infections in domestic cats from the Brazilian semiarid region

Feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) are retroviruses of great importance for domestic cats with a worldwide distribution. A retrospective study was conducted to determine the epidemiological and clinicopathological aspects of the infection by FIV and FeLV in cats from the Brazilian semiarid region. Cats treated between 2011 and 2021 at the teaching veterinary hospital of the Federal Rural University of the Semi-Arid Region that were submitted to a point-of-care (POC) test to detect anti-FIV IgG antibodies and FeLV antigen were enrolled in the study. Overall, 454 cats were selected, of which 30.2% [95% CI = 26.0% - 34.3%] were FIV-positive, 1.1% [95% CI = 0.9% - 1.2%] were FeLV-positive, and 0.7% [95% CI = 0.1% - 1.3%] were coinfected by both retroviruses. No statistical association was found between the studied retroviruses (P = 0.144). Multivariable analysis detected significant associations between FIV infection and male sex [OR = 5.7, 95% CI = 3.0-10.7, P < 0.0001), age between 19 and 78 months [OR = 5.2, 95% CI = 2.2-12.1, P < 0.0001], age greater than 78 months [OR = 12.8, 95% CI = 5.1-31.9, P < 0.0001], crossbreed [OR = 4.1, 95% CI = 1.2-13.4, P = 0.021], the presence of oral disease [OR = 2.1, 95% CI = 1.3-3.4, P = 0.004], reduced red blood cell (RBC) count [OR = 3.7, 95% CI = 1.9-7.2, P < 0.0001], and an albumin:globulin (A:G) ratio lower than 0.6 [OR = 3.4, 95% CI = 1.6-7.1, P = 0.001]. No statistical analyses were performed for FeLV infection due to the low number of positive animals. In the quantitative analyses of hematological parameters, FIV-positive cats presented lower values for RBC, hemoglobin, hematocrit, lymphocytes, and platelets compared to the negative animals. In the biochemical profile, cats infected with FIV showed higher creatinine, urea, total protein, and globulin values, while lower values for albumin and A:G ratio were observed (P < 0.05). The findings of this study characterized the prevalence, clinicopathological findings, and risk factors associated with FIV and FeLV in cats from the Brazilian semiarid region. They may help support veterinary practitioners in diagnosing feline retroviruses. The FIV prevalence observed is among the highest reported in Brazil, demonstrating the need for prevention and control strategies for this retrovirus.

Assessing the potential efficacy of 830-nanometer low-level laser therapy in cats: Extraoral applications

Background and Aim

Low-level laser therapy (LLLT) has shown benefits as an alternative treatment of feline chronic gingivostomatitis by reducing pain and inflammation within the oral cavity. Extraoral application technique in cats provides more comfort compared to intraoral application. However, the efficacy of LLLT through buccal tissue is still controversial. This study aimed to investigate the penetration efficacy of LLLT using 830 nm continuous waves with various settings and different application techniques.

Materials and Methods

Twenty-four healthy cats were included in this study. The wavelength of LLLT was 830 nm with an output power of 200 mW through extraoral application, using fluences of 2 and 6 J/cm2 in continuous-wave mode. This study compared different distances (contact and non-contact) and three different transmission media (absent media, alcohol, and normal saline solution). Measurement of the laser power within the oral cavity is represented as the mean output power (MOP).

Results

Penetration efficacy was detectable for all fluences, distances, and transmission media, with an average buccal thickness of 2.68 mm. MOP did not differ between fluences of 2 and 6 J/cm2 (p = 0.19). In the absence of media, MOP was significantly higher compared with alcohol (p < 0.05) but was not significantly different from normal saline solution (p = 0.26).

Conclusion

Extraoral application of LLLT demonstrated penetration efficacy through the buccal tissue with both contact and non-contact skin (<10 mm). This is a potential alternative treatment for oral diseases in clinical practice. However, there is a need for further study on the efficacy of treatment in clinical practice.

Mesenchymal Stem Cell-Derived Exosomes in Various Chronic Liver Diseases: Hype or Hope?

Chronic liver conditions are associated with high mortality rates and have a large adverse effect on human well-being as well as a significant financial burden. Currently, the only effective treatment available for the effects of liver failure and cirrhosis resulting from the progression of several chronic liver diseases is liver transplantation carried out at the original location. This implies that developing novel and effective treatments is imperative. Regenerative medicine has long been associated with stem cell therapy. Mesenchymal stem cells (MSCs), a type of cell with great differentiation potential, have become the preferred source for stem cell therapy. According to recent studies, MSCs' paracrine products-rather than their capacity for differentiation-play a significant therapeutic effect. MSC exosomes, a type of extracellular vesicle (MSC-EV), came into view as the paracrine substances of MSCs. According to research, MSC exosomes can maintain tissue homeostasis, which is necessary for healthy tissue function. All tissues contain them, and they take part in a variety of biological activities that support cellular activity and tissue regeneration in order to preserve tissue homeostasis. The outcomes support the use of MSCs and the exosomes they produce as a therapeutic option for a range of diseases. This review provides a brief overview of the source of MSC-EVs and outlines their physiological roles and biochemical capabilities. The elucidation of the role of MSC-EVs in the recovery and repair of hepatic tissues, as well as their contribution to maintaining tissue homeostasis, is discussed in relation to different chronic liver diseases. This review aims to provide new insights into the unique roles that MSC-EVs play in the treatment of chronic liver diseases.

The Oral Microbiome across Oral Sites in Cats with Chronic Gingivostomatitis, Periodontal Disease, and Tooth Resorption Compared with Healthy Cats

Feline chronic gingivostomatitis (FCGS) is a chronic mucosal and gingival inflammatory disease in which pathogenesis remains unclear. Interactions between the host inflammatory process, the host immune response, and the oral microbiome are implicated in this pathogenesis. To begin to understand this disease and the impact of the microbiome to host inflammatory disease states, we collected sterile noninvasive plaque biofilm samples from ten distinct sites within the oral cavity in cats with stomatitis (n = 12), healthy cats (n = 9), and cats with tooth resorption or periodontitis (n = 11). Analysis of full-length 16S rRNA gene sequences indicated that the microbiomes of cats with FCGS presented marked dysbiosis at multiple oral sites. Additionally, microbiome beta diversity varied with oral condition, indicating that stomatitis, periodontitis, and/or tooth resorption influence the microbiome differently. Lastly, we found that the microbiomes of swabs taken from the oral cavity were comparable to those taken from plaque using endodontic paper points, validating this as another sampling method. Collectively, our work furthers our understanding of the dysbiosis and composition of bacteria in the oral microbiome in FCGS, with hopes of contributing to the prevention, diagnosis, and treatment of this challenging condition in felines.

Dietary omega-3 fatty acids in the management of feline periodontal disease: What is the evidence?

Periodontal disease is an oral disorder with high prevalence in cats from 2 years of age, resulting from an inflammatory response against bacterial plaque. Treatment depends on the stage of the disease and may include dental scaling, local application of perioceutics, tissue regeneration and/or even tooth extraction and periodontal surgery. As multimodal therapy is often required, new strategies have been developed to improve the therapeutic response in these patients. Adjuvant use of omega-3 fatty acids has been reported in humans with periodontal disease, but the current evidence of its effect in companion animals, especially cats, is still considered to be scarce and conflicting. This review describes the state of the art regarding feline periodontal disease and seeks to clarify the potential effect of omega-3 fatty acids on its clinical management in light of the evidence available in the current literature.

Transcriptomic signatures of feline chronic gingivostomatitis are influenced by upregulated IL6

Feline chronic gingivostomatitis (FCGS) is a relatively common and debilitating disease characterized by bilateral inflammation and ulceration of the caudal oral mucosa, alveolar and buccal mucosa, and varying degrees of periodontal disease. The etiopathogenesis of FCGS remains unresolved. In this study, we performed bulk RNA-seq molecular profiling of affected tissues derived from a cohort of client-owned cats with FCGS compared to tissues from unaffected animals, to identify candidate genes and pathways that can help guide future exploration of novel clinical solutions. We complemented transcriptomic findings with immunohistochemistry and in situ hybridization assays to better understand the biological significance of the results and performed RNA-seq validation of biologically relevant differentially expressed genes using qPCR assays to demonstrate technical reproducibility. Transcriptomic profiles of oral mucosal tissues in cats with FCGS are enriched with immune- and inflammation-related genes and pathways that appear to be largely influenced by IL6, and include NFKB, JAK/STAT, IL-17 and IFN type I and II signaling, offering new opportunities to develop novel clinical applications based on a more rational understanding of the disease.

Feline calicivirus and natural killer cells: A study of its relationship in chronic gingivostomatitis

Background and Aims

Feline chronic gingivostomatitis (FCGS) is a frequent chronic inflammatory condition in the oral cavity with an etiopathogenesis not completely identified. This study aimed to contribute to the knowledge of FCGS by identifying the presence of feline calicivirus (FCV) antigens and natural killer (NK) cells and comparing them.

Materials and Methods

Forty biopsies from the oral mucosa of cats diagnosed with chronic gingivostomatitis were subjected to immunohistochemical techniques to evaluate cells with FCV antigens and NK cells positive for CD56.

Results

NK cells were identified in all samples, with an average of 725.3 ± 409.1 cells. Regarding FCV, it was identified in 18 out of 30 samples (60%), with a different number of cells with virus in between the analyzed cases. In all cases, the number of cells infected with FCV was lower than the number of NK cells present in the same samples, but there was no statistical association between them.

Conclusion

This preliminary study shows that NK cells are present in gingivostomatitis lesions not exclusively caused by FCV-stimulus, as only 60% of all cases were positive for this virus, but other antigens should be considered in the etiology of FCGS.

Mesenchymal Stem Cells: Generalities and Clinical Significance in Feline and Canine Medicine

Mesenchymal stem cells (MSCs) are multipotent cells: they can proliferate like undifferentiated cells and have the ability to differentiate into different types of cells. A considerable amount of research focuses on the potential therapeutic benefits of MSCs, such as cell therapy or tissue regeneration, and MSCs are considered powerful tools in veterinary regenerative medicine. They are the leading type of adult stem cells in clinical trials owing to their immunosuppressive, immunomodulatory, and anti-inflammatory properties, as well as their low teratogenic risk compared with pluripotent stem cells. The present review details the current understanding of the fundamental biology of MSCs. We focus on MSCs' properties and their characteristics with the goal of providing an overview of therapeutic innovations based on MSCs in canines and felines.

Cross-sectional characterization of renal function in cats with caudal stomatitis

OBJECTIVES

The objective of the study was to compare renal functional biomarkers in cats and in caudal stomatitis (CS) and in age-matched control cats.

METHODS

A cross-sectional, case-control study was conducted on 44 client-owned cats with CS that were prospectively enrolled and evaluated for a Comprehensive Oral Health Assessment and Treatment at one of four institutions. Renal function was assessed with measurement of serum creatinine, urea nitrogen, serum symmetric dimethylarginine, urinalysis, urine protein:creatinine ratio and urine protein electrophoresis. Affected gingiva was biopsied to confirm the diagnosis of stomatitis. Renal biochemical analyses from the experimental group were compared with those of 44 age-matched controls without CS enrolled prospectively or retrospectively after presenting to the primary institution for routine healthcare. Control cats were included if they were clinically stable, their chronic illnesses were well managed and minimal dental disease was present on examination. Renal biomarkers were compared between groups using a t-test or the Mann-Whitney U-test. Frequency of azotemia, proteinuria and the clinical diagnosis of renal disease were compared using Fisher's exact test.

RESULTS

Relative to the control group, cats in the CS group had significantly lower serum creatinine (P <0.001) and albumin concentrations (P <0.001), urine specific gravity (P = 0.024) and hematocrit (P = 0.003), and higher serum phosphorus (P <0.001), potassium (P <0.001) and globulin concentrations (P <0.001), white blood cell count (P <0.001) and urine protein:creatinine ratio (P = 0.009). There were no significant differences in serum symmetric dimethylarginine or urea nitrogen concentrations. No clinically significant findings were noted on urine protein electrophoresis. There were no significant differences in the frequency of azotemia, proteinuria or renal disease categories between the two groups.

CONCLUSIONS AND RELEVANCE

The present study does not demonstrate a significant difference in the frequency of kidney disease between cats with and without CS. Longitudinal evaluation is warranted to investigate the relationship between renal disease and CS.

Transcriptomic signatures of feline chronic gingivostomatitis are influenced by upregulated IL6

Feline chronic gingivostomatitis (FCGS) is a relatively common and debilitating disease characterized by bilateral inflammation and ulceration of the caudal oral mucosa, alveolar and buccal mucosa, and varying degrees of periodontal disease. The etiopathogenesis of FCGS remains unresolved. In this study, we performed bulk RNA-seq molecular profiling of affected tissues derived from a cohort of client-owned cats with FCGS compared to tissues from unaffected animals, to identify candidate genes and pathways that can help guide future exploration of novel clinical solutions. We complemented transcriptomic findings with immunohistochemistry and in situ hybridization assays to better understand the biological significance of the results and performed RNA-seq validation of selected differentially expressed genes using qPCR assays to demonstrate technical reproducibility. Transcriptomic profiles of oral mucosal tissues in cats with FCGS are enriched with immune- and inflammation-related genes and pathways that appear to be largely influenced by IL6 , and include NFKB, JAK/STAT, IL-17 and IFN type I and II signaling, offering new opportunities to develop novel clinical applications based on a more rational understanding of the disease.

Prevalence of feline chronic gingivostomatitis in feral cats and its risk factors

OBJECTIVES

This study investigated the prevalence of feline chronic gingivostomatitis in urban feral cats in South Korea and analysed its risk factors.

METHODS

Three hundred and forty-five feral cats that visited the hospital for neutering using a trap-neuter-return approach were screened for feline chronic gingivostomatitis based on clinical criteria. In addition, we determined if body weight, sex and the presence of tongue lesions are risk factors for feline chronic gingivostomatitis. The difference in severity due to the presence or absence of risk factors, and the relationship between gross findings and histopathological lesions, were analysed by grading lesion severity.

RESULTS

Feline chronic gingivostomatitis was diagnosed in 92 cats. Disease prevalence did not significantly differ with body weight and sex but was significantly related to tongue lesions.

CONCLUSIONS AND RELEVANCE

The prevalence of feline chronic gingivostomatitis in urban feral cats in South Korea was 26.6%. It was significantly more prevalent in cats that had tongue lesions. Severity was also significantly associated with tongue lesions. Feline chronic gingivostomatitis may be associated with an infectious agent that causes tongue lesions.

Mesenchymal stromal cell therapy for feline chronic gingivostomatitis: Long term experience

Introduction

Mesenchymal stromal cells (MSC) therapy has emerged as a potential treatment option for refractory FCGS. However, there is a lack of long-term data on the use of MSC therapy in cats. This study aimed to evaluate the long-term safety and efficacy of MSC therapy for FCGS and investigate potential factors associated with treatment outcomes.

Methods

This study was a retrospective evaluation of 38 client-owned cats with refractory FCGS who received MSC therapy. Medical records, histopathology, and the Stomatitis Activity Disease Index (SDAI) were reviewed. Correlations of the long-term follow-up success rates with SDAI and cell line type used were conducted. A client survey was also performed to assess side effect occurrence, quality-of-life following treatment, and overall treatment satisfaction.

Results

Long-term follow-up ranged from 2 to 9 years post-MSC treatment. The overall positive response rate to MSC treatment was 65.5%, with 58.6% of cats exhibiting permanent improvement or cure. Adverse effects occurring during or immediately after treatment were noted in 34.2% of cases, the majority being transient, self-resolving transfusion-like reactions. No long-term adverse events were noted. No significant correlation in outcome was detected between allogeneic and autologous MSC treatment (p = 0.871) or the severity of the SDAI at entry (p = 0.848) or exit (p = 0.166), or the delta SDAI between entry and exit (p = 0.178). The status 6 months (none to partial improvement vs. substantial improvement to resolution) post-therapy was a predictor of long-term response (value of p < 0.041). Most clients were satisfied with the treatment and outcomes, with 90.6% willing to pursue treatment again, given a similar situation.

Discussion

The results of this study support the use of both autologous and allogeneic MSC as an efficacious and safe therapeutic option for refractory FCGS.

Placenta‐derived mesenchymal stromal cells as a treatment for refractory chronic gingivostomatitis in cats: eight cases (2018)

OBJECTIVES

The aim of this case series was to collect preliminary data on safety and efficacy of treating cats suffering from refractory feline chronic gingivostomatitis with a single intravenous therapy of cryopreserved placenta-derived mesenchymal stromal cells.

MATERIALS AND METHODS

We planned the prospective inclusion of cats suffering from refractory chronic gingivostomatitis in three veterinary clinics. All cats received a single infusion of 10×10⁶ cryopreserved cells. Follow-up evaluations were done at day 15 and at 2-, 3- and 6-months following infusion. Clinical disease severity was evaluated by dental specialists using a published stomatitis disease activity index scoring system coupled with an owners' assessment questionnaire.

RESULTS

All eight cats attended all follow up visits. Cryopreserved ready-to-use placenta-derived cells administered systemically were safe and resulted in notable clinical improvement in all cats as reported by stomatitis disease activity index scoring and owner's survey.

CLINICAL SIGNIFICANCE

Infusion of cryopreserved freshly thawed placenta-derived mesenchymal stromal cells appears to promote clinical and consequently behavioural benefits in cats with refractory chronic gingivostomatitis after having undergone full-mouth or premolar-molar tooth extraction. Future randomised studies are required to confirm safety and efficacy of this treatment.

Detection and genetic characterization of feline retroviruses in domestic cats with different clinical signs and hematological alterations

Feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) are globally distributed retroviruses that infect domestic cats and cause various syndromes that can lead to death. The aim of this study was to detect and genotype feline retroviruses in Mexican domestic cats. We used PCR assays to identify proviral DNA and viral RNA in 50 domestic cats with different clinical signs and hematological alterations. Endogenous FeLV (enFeLV) was identified in the genomic DNA of all cats in the study, and we detected transcripts of the LTR region of enFeLV in 48 individuals. Exogenous FeLV (exFeLV) was found in 13 cats. Furthermore, we detected FIV proviral DNA in 10 cats. The enFeLV sequences were shown to be the most variable, while the exFeLV sequences were highly conserved and related to previously reported subgroup A sequences. Sequencing of the FIV gag gene revealed the presence of subtype B in the infected cats.

Feline Oral Squamous Cell Carcinoma: A Critical Review of Etiologic Factors

Simple Summary

Feline oral squamous cell carcinoma (FOSCC) is the most common oral neoplasia in cats. This malignant tumor is locally invasive, has a high mortality rate, and its etiology is not yet known. A critical review about the potential etiologic factors of FOSCC was performed, considering publications between 2000 and 2022. The initial search resulted in 553 publications, with only 26 of these being included in the review. Sixteen studies were related to viral etiology and nine related to environmental factors such as exposure to tobacco smoke, ectoparasitic products, and the presence of oral comorbidities. When evaluated, feline papillomavirus was detected in 16.2% of samples of FOSCC. In the three studies focused on exposure to tobacco smoke, 35.2% (30/85) of cats with FOSCC had a history of this exposure. Among 485 cats with FOSCC, 6.4% had dental and oral pathology. The present study demonstrates that the available evidence on the etiology of FOSCC is still limited, however, there has been increasing interest in this topic.

Abstract

Feline oral squamous cell carcinoma (FOSCC) is the most common oral neoplasia in cats. This malignant tumor is locally invasive, has a high mortality rate, and its etiology is not yet known. In humans, head and neck squamous cell carcinoma is associated with tobacco smoke, alcohol consumption, and human papillomavirus infection. Herein, a critical review about the potential etiologic factors of FOSCC was performed, considering publications between 2000 and 2022, aiming to synthesize all available scientific evidence regarding this issue. Recommendations of the PRISMA statement and the Cochrane Collaboration were followed and the PubMed database searched by using the MeSH terms MeSH terms “oral”, “mouth”, “lingual”, “labial”, “gingiva”, “carcinoma”, “squamous”, and “feline”. The selection process for eligible studies was based on specific inclusion and exclusion criteria and the quality of the studies assessed. The initial search resulted in 553 publications, with only 26 of these being included in the review. Sixteen studies were related to viral etiology and nine related to environmental factors such as exposure to tobacco smoke, ectoparasitic products, and the presence of oral comorbidities. When evaluated, feline papillomavirus was detected in 16.2% of samples of FOSCC. In the three studies focused on exposure to tobacco smoke, 35.2% (30/85) of cats with FOSCC had a history of this exposure. The consumption of canned food and the use of deworming collars were associated, in only one publication, with a risk of neoplasia increased by 4.7 and 5.3 times, respectively. Among 485 cats with FOSCC, 6.4% had dental and oral pathology (i.e., periodontal disease or feline chronic gingivostomatitis). The present study demonstrates that the available evidence on the etiology of FOSCC is still limited, however, there has been an increasing interest on this topic. To better understand the role of the possible etiological factors of this aggressive disease, and model for its human counterpart, large, prospective multi-institutional studies are needed.

Influence of Gallic Acid-Containing Mouth Spray on Dental Health and Oral Microbiota of Healthy Cats—A Pilot Study

Simple Summary

Periodontal diseases are common dental issues in cats. Oral care supplements were used to prevent diseases and maintain oral health. Moreover, maintaining a healthy oral microbiome is crucial for oral health. Therefore, we have developed a gallic acid-containing mouth spray and studied its effect on oral microbiota and dental health in healthy cats. The results revealed that the gingival and plaque indexes were improved after 42 days of mouth spray treatment in cats. The mouth spray treatment also reduced the abundance of harmful bacterial load and supported the growth of normal oral microbiota. This preliminary study recommended that the gallic acid-containing mouth spray could be an essential oral product to improve the oral hygiene of the cats.

Abstract

This pilot study aimed to investigate the effects of gallic acid-containing mouth spray on oral microbiota in healthy cat subjects. Forty healthy cats were recruited and randomly allocated to the control (G1; n = 20) and treatment groups (G2; n = 20). The cats were treated with mouth spray twice daily for 42 days. The changes in the gingival index (GI) and plaque index (PI) were measured at baseline (day 0) and end of the study (42nd day). The changes in the oral microbial composition of representative animals (control, n = 9; and treatment, n = 8) were also evaluated at baseline and end of the study. Oral microbial composition was assessed by amplifying the V1–V3 region of the 16S rRNA gene from supragingival dental plaque DNA extracts. The sequences were annotated using the QIIME 2.0. The GI and PI were significantly reduced after 42 days of treatment. The deep sequencing revealed that mouth spray influenced the cats’ oral microbiome and was significantly diverse. About 20 phyla and 59 species were observed after 42 days of mouth spray usage in cats’ oral microbiota. The number of operational taxonomic units (OTUs) of post-treatment samples (PoTS) of G2 was greatly reduced compared to other samples. Further analysis revealed that mouth spray acts substantially against Desulfomicrobium orale, one of the known pathogens in periodontal disease. The mouth spray efficiently reduced the growth of 22 species and uprooted 17 species. Moreover, the mouth spray supported the growth of normal oral microbiota, including Moraxella and Neisseria species. The preliminary study suggested that the gallic acids-containing mouth spray could be an essential oral product to improve the oral hygiene of the cats. Moreover, further studies are needed to confirm the beneficial effect of mouth spray on cats.

Environmental risk factors for the development of oral squamous cell carcinoma in cats

BACKGROUND

Risk factors for oral squamous cell carcinoma (OSCC) in cats are derived from a single study dated almost 20 years ago. The relationship between inflammation of oral tissues and OSCC is still unclear.

OBJECTIVES

To investigate previously proposed and novel potential risk factors for OSCC development, including oral inflammatory diseases.

ANIMALS

Hundred cats with OSCC, 70 cats with chronic gingivostomatitis (CGS), 63 cats with periodontal disease (PD), and 500 controls.

METHODS

Prospective, observational case-control study. Cats with OSCC were compared with an age-matched control sample of client-owned cats and cats with CGS or PD. Owners of cats completed an anonymous questionnaire including demographic, environmental and lifestyle information.

RESULTS

On multivariable logistic regression, covariates significantly associated with an increased risk of OSCC were rural environment (OR: 1.77; 95% CI: 1.03-3.04; P = .04), outdoor access (OR: 1.68; 95% CI: 1.07-2.63; P = .02), environmental tobacco smoke (OR: 1.77; 95% CI: 1.05-3; P = .03), and petfood containing chemical additives (OR: 1.98; 95% CI: 1.04-3.76; P = .04). Risk factors shared with CGS and PD were outdoor access and petfood containing chemical additives, respectively. A history of oral inflammation was reported in 35% of cats with OSCC but did not emerge as a risk factor.

CONCLUSIONS AND CLINICAL IMPORTANCE

The study proposes novel potential risk factors for OSCC in cats. Although a history of inflammatory oral disease was not significantly more frequent compared with random age-matched controls, OSCC shared several risk factors with CGS and PD.

Secretory Profile of Adipose-Tissue-Derived Mesenchymal Stem Cells from Cats with Calicivirus-Positive Severe Chronic Gingivostomatitis

The feline calicivirus (FCV) causes infections in cats all over the world and seems to be related to a broad variety of clinical presentations, such as feline chronic gingivostomatitis (FCGS), a severe oral pathology in cats. Although its etiopathogeny is largely unknown, FCV infection is likely to be a main predisposing factor for developing this pathology. During recent years, new strategies for treating FCGS have been proposed, based on the use of mesenchymal stem cells (MSC) and their regenerative and immunomodulatory properties. The main mechanism of action of MSC seems to be paracrine, due to the secretion of many biomolecules with different biological functions (secretome). Currently, several pathologies in humans have been shown to be related to functional alterations of the patient’s MSCs. However, the possible roles that altered MSCs might have in different diseases, including virus-mediated diseases, remain unknown. We have recently demonstrated that the exosomes produced by the adipose-tissue-derived MSCs (fAd-MSCs) from cats suffering from FCV-positive severe and refractory FCGS showed altered protein contents. Based on these findings, the goal of this work was to analyze the proteomic profile of the secretome produced by feline adipose-tissue-derived MSCs (fAd-MSCs) from FCV-positive patients with FCGS, in order to identify differences between them and to increase our knowledge of the etiopathogenesis of this disease. We used high-resolution mass spectrometry and functional enrichment analysis with Gene Ontology to compare the secretomes produced by the fAd-MSCs of healthy and calicivirus-positive FCGS cats. We found that the fAd-MSCs from cats with FCGS had an increased expression of pro-inflammatory cytokines and an altered proteomic profile compared to the secretome produced by cells from healthy cats. These findings help us gain insight on the roles of MSCs and their possible relation to FCGS, and may be useful for selecting specific biomarkers and for identifying new therapeutic targets.

The oromaxillofacial region as a model for a one-health approach in regenerative medicine

The concept of a one-health approach in regenerative medicine has gained tremendous momentum in the scientific and public communities in recent years. Knowledge derived from this approach informs innovative biomedical research, clinical trials, and practice. The ultimate goal is to translate regenerative strategies for curing diseases and improving the quality of life in animals and people. Building and fostering strong and enthusiastic interdisciplinary and transdisciplinary collaboration between teams with a wide range of expertise and backgrounds is the cornerstone to the success of the one-health approach and translational sciences. The veterinarian's role in conducting clinical trials in client-owned animals with naturally occurring diseases is critical and unique as it may potentially inform human clinical trials. The veterinary regenerative medicine and surgery field is on a steep trajectory of discoveries and innovations. This manuscript focuses on oromaxillofacial-region regeneration to exemplify how the concept of interdisciplinary and transdisciplinary collaboration and the one-health approach influenced the authors' work experience at the University of California-Davis.

Occurrence of Antimicrobial Resistance Genes in the Oral Cavity of Cats with Chronic Gingivostomatitis

Simple Summary

Oral disease in cats is a significant concern in the small animal practice setting. The specific cause of this disease is inadequately understood; however, antibiotics are commonly used for the management, although many cats respond poorly to these treatments. Antibiotics have been overused and misused in the context of both human and veterinary medicine. Consequently, many antimicrobial drugs are becoming less effective in treating infections. This study aimed to evaluate the presence of antimicrobial resistance genes in swabs obtained from the mouth of cats. Moreover, the study looked at simultaneous occurrence between these genes and one type of oral fungi. We found that antimicrobial resistance genes are extremely common in both clinically healthy and sick cats. Furthermore, we established that Malassezia (a type of fungi) co-occurs with some resistance genes. The findings are important because antimicrobial resistance genes present in the mouth of cats have the potential to transfer to humans and thereby make certain antibiotics less effective.

Abstract

Feline chronic gingivostomatitis (FCGS) is a severe immune-mediated inflammatory disease with concurrent oral dysbiosis (bacterial and fungal). Broad-spectrum antibiotics are used empirically in FCGS. Still, neither the occurrence of antimicrobial-resistant (AMR) bacteria nor potential patterns of co-occurrence between AMR genes and fungi have been documented in FCGS. This study explored the differential occurrence of AMR genes and the co-occurrence of AMR genes with oral fungal species. Briefly, 14 clinically healthy (CH) cats and 14 cats with FCGS were included. Using a sterile swab, oral tissue surfaces were sampled and submitted for 16S rRNA and ITS-2 next-generation DNA sequencing. Microbial DNA was analyzed using a proprietary curated database targeting AMR genes found in bacterial pathogens. The co-occurrence of AMR genes and fungi was tested using point biserial correlation. A total of 21 and 23 different AMR genes were detected in CH and FCGS cats, respectively. A comparison of AMR-gene frequencies between groups revealed statistically significant differences in the occurrence of genes conferring resistance to aminoglycosides (ant4Ib), beta-lactam (mecA), and macrolides (mphD and mphC). Two AMR genes (mecA and mphD) showed statistically significant co-occurrence with Malassezia restricta. In conclusion, resistance to clinically relevant antibiotics, such as beta-lactams and macrolides, is a significant cause for concern in the context of both feline and human medicine.

Management of Severe Oral Inflammatory Conditions in Dogs and Cats

Severe oral inflammatory disease is not uncommon in the mouths of canine and feline patients. An approach to oral diagnosis is offered. This article discusses a brief review of important points in the oral diagnosis and management of main canine (canine chronic ulcerative stomatitis (CCUS), eosinophilic stomatitis, and Wegener's granulomatosis (WG)) and feline diseases (feline gingivostomatitis/caudal stomatitis, oral eosinophilic lesions, pyogenic granuloma, and autoimmune diseases with oral manifestations), and-whereby possible-information about the current understanding of disease pathogenesis and treatment is offered.

A Case Series Analysis of Dental Extractions' Outcome in Cats with Chronic Gingivostomatitis Carrying Retroviral Disease

Simple Summary

Feline chronic gingivostomatitis (FCGS) is a chronic, painful, oral inflammatory disease, which can be associated with retroviral disease comorbidity’s, namely feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV). A total 111 case series of cats affected by this oral disease, treated with dental extractions, were analyzed retrospectively, considering if they carried or not one of these retroviral diseases. Cats with lingual ulcers, independently from their retroviral status, were 2.7 times more prone to have a worse response to dental extractions than cats without lingual ulcers. When compared with cats without retroviral disease, FeLV-positive cats presented less proliferative lesions and tended to have more lingual ulcers. Furthermore, these cats had a significantly worse outcome, with 7.5 times more chances of having no improvement.

Abstract

This study aims to evaluate and compare the clinical outcome after dental extractions of cats with FCGS infected with feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV). A retrospective case series included cats with diagnosis of FCGS, availability of detailed clinical records, full-mouth dental radiographs, and retroviral disease test results. Effectiveness of surgical treatment (EOT) was registered. Three groups were defined: control, FIV and FeLV. In this study, 111 cats were included: 60 controls, 29 FIV- and 22 FeLV-positive cats. When compared with control cases, FeLV-positive cats had significantly less proliferative stomatitis lesions, and they tended to have more lingual ulcers. Concurrently, FeLV-positive cats had significantly less tooth resorptive lesions. No other significant differences in FCGS clinical signs were found between groups. FeLV-positive cats had a significantly worse outcome after dental extractions compared to the other groups. In fact, FeLV-positive cats had 7.5 times more chances of having no improvement after dental extractions. This study concludes that the response to dental extractions in FeLV-positive cats is significantly worse, when comparing to cats that do not carry retroviral disease. Therefore, it is important to acknowledge the effect of FeLV status on the prognosis of these cats.

Feline adipose-derived mesenchymal stem cells induce effector phenotype and enhance cytolytic function of CD8+ T cells

BACKGROUND

Feline adipose-derived mesenchymal stem cells (ASCs) engage with a variety of immune cells and have been used in several clinical trials for the treatment of inflammatory and immune-dysregulated diseases in cats, but the impact they exert on the functional characteristics on T cells, particularly CD8+ T cells, remains to be elucidated.

METHODS

Modified mixed leukocyte reaction was performed between feline ASCs and PBMCs. Changes of cell cycle stages, phenotype and cellular senescence were determined through flow cytometry and gene expression analysis. Cytotoxicity assay was performed to evaluate CD8+ T cell effector function.

RESULTS

Feline ASCs induce cell cycle arrest on CD8+ T cells in a contact-dependent manner, downregulate CD8 surface expression, and shift their phenotype toward terminally differentiated effector cells (CD57+, CD45R+, CD62L-). CD8 T cells interacted with feline ASCs also upregulated granzyme B, IL-2 and KLRG-1 expression and have enhanced cytotoxic potential, evident by the increased percentage of lysis on target cells.

CONCLUSIONS

Our findings suggest that feline ASCs (1) alter CD8+ T cells toward terminally differentiated, proinflammatory effector phenotype with limited proliferative capacity, and (2) enhance their cytotoxic potential through granzyme B upregulation. These cytotoxic CD8+ T cells could aid in disease cure in cases caused by an underlying, unresolved viral infection.

Altered Proteomic Profile of Adipose Tissue-Derived Mesenchymal Stem Cell Exosomes from Cats with Severe Chronic Gingivostomatitis

Simple Summary

Feline chronic gingivostomatitis (FCGS) is a common pathology in cats, related to an aberrant immune response. The cause of FCGS remains elusive, despite extensive investigations. A multitude of conditions and infectious agents have been related, without proof of causation, as follows: virus, bacteria, environmental stress, hypersensitivity, etc. In recent years, therapies based on feline adipose-derived mesenchymal stem cells (fAd-MSC) have become an interesting alternative for the treatment of different complex pathologies in cats. Mesenchymal stem cells secrete a wide variety of therapeutic elements, such as bioactive molecules and extracellular vesicles, such as exosomes. It is essential to characterize these elements, to better understand their mechanisms of action. In this study, we show, for the first time, that the proteomic profile of fAd-MSC-derived exosomes, from calicivirus-positive patients with severe FCGS, is altered. Using bioinformatic tools, we have demonstrated the existence of different proteins in the exosomes from diseased patients, responsible for an altered biological effect. In addition, the exosomes do not only experience changes in their cargo, but are also produced in larger quantities. This study might contribute to the better prediction of the clinical outcomes of mesenchymal stem cell treatments in veterinary patients with immune-mediated diseases, such as FCGS.

Abstract

Feline chronic gingivostomatitis (FCGS) is a pathology with a complicated therapeutic approach and with a prevalence between 0.7 and 12%. Although the etiology of the disease is diverse, feline calicivirus infection is known to be a predisposing factor. To date, the available treatment helps in controlling the disease, but cannot always provide a cure, which leads to a high percentage of refractory animals. Mesenchymal stem cells (MSCs) play a pivotal role in the homeostasis and reparation of different tissues and have the ability to modulate the immune system responses. This ability is, in part, due to the capacity of exosomes to play a part in intercellular cell communication. However, the precise role of MSC-derived exosomes and their alterations in immunocompromised pathologies remains unknown, especially in veterinary patients. The goal of this work was to analyze the proteomic profile of feline adipose tissue-derived MSCs (fAd-MSCs) from calicivirus-positive FCGS patients, and to detect possible modifications of the exosomal cargo, to gain better knowledge of the disease’s etiopathogenesis. Using high-resolution mass spectrometry and functional enrichment analysis with Gene Ontology, exosomes isolated from the fAd-MSCs of five healthy cats and five calicivirus-positive FCGS patients, were pooled and compared. The results showed that the fAd-MSCs from cats suffering from FCGS not only had a higher exosome production, but also their exosomes showed significant alterations in their proteomic profile. Eight proteins were exclusively found in the exosomes from the FCGS group, and five proteins could only be found in the exosomes from the healthy cats. When comparing the exosomal cargo between the two groups, significant upregulation of 17 and downregulation of 13 proteins were detected in the FCGS group compared to the control group. These findings shed light on new perspectives on the roles of MSCs and their relation to this disease, which may help in identifying new therapeutic targets and selecting specific biomarkers.

Expression of cannabinoid and cannabinoid-related receptors in the oral mucosa of healthy cats and cats with chronic gingivostomatitis

OBJECTIVES

Feline chronic gingivostomatitis (FCGS) is an oral disease. Cats with FCGS experience intense oral pain. Some cats remain refractory to current therapies based on dental extraction and adjuvant medical treatment; it is therefore necessary to investigate alternative therapeutic targets involved in inflammatory mechanisms and pain, namely the endocannabinoid system (ECS). The present study investigated the expression of cannabinoid receptors type 1 (CB1R) and 2 (CB2R), and cannabinoid-related receptors G protein-coupled receptor 55 (GPR55), transient receptor potential ankyrin 1 (TRPA1) and serotonin 1a receptor (5-HT1aR), in the oral mucosa of healthy cats to determine whether there was altered expression and distribution in cats with FCGS.

METHODS

Samples of caudal oral mucosa were collected from eight control cats (CTRL cats) and from eight cats with FCGS (FCGS cats). Tissue samples were processed using an immunofluorescence assay with cat-specific antibodies, and the immunolabelling of the receptors studied was semiquantitatively evaluated.

RESULTS

The mucosal epithelium of the CTRL cats showed CB1R, TRPA1 and 5-HT1aR immunoreactivity (IR), while CB2R and GPR55 IR were generally not expressed. In the CTRL cats, the subepithelial inflammatory cells expressed CB2R, GPR55 and 5-HT1aR IR. In the FCGS cats, all the receptors studied were markedly upregulated in the epithelium and inflammatory infiltrate.

CONCLUSIONS AND RELEVANCE

Cannabinoid and cannabinoid-related receptors are widely expressed in the oral mucosa of healthy cats and are upregulated during the course of FCGS. The presence of cannabinoid and cannabinoid-related receptors in healthy tissues suggests the possible role of the ECS in the homeostasis of the feline oral mucosa, while their overexpression in the inflamed tissues of FCGS cats suggests the involvement of the ECS in the pathogenesis of this disease, with a possible role in the related inflammation and pain. Based on the present findings, ECS could be considered a potential therapeutic target for patients with FCGS.

Characterization of Oral Microbiota in Cats: Novel Insights on the Potential Role of Fungi in Feline Chronic Gingivostomatitis

Previous studies have suggested the involvement of viral and bacterial components in the initiation and progression of feline chronic gingivostomatitis (FCGS), but the role of fungi remains entirely unknown. This pilot study aimed to investigate the bacteriome and mycobiome in feline oral health and disease. Physical exams, including oral health assessment, of privately owned, clinically healthy (CH) cats (n = 14) and cats affected by FCGS (n = 14) were performed. Using a sterile swab, oral tissue surfaces of CH and FCGS cats were sampled and submitted for 16S rRNA and ITS-2 next-generation DNA sequencing. A high number of fungal species (n = 186) was detected, with Malassezia restricta, Malassezia arunalokei, Cladosporium penidielloides/salinae, and Aspergillaceae sp. being significantly enriched in FCGS samples, and Saccharomyces cerevisiae in CH samples. The bacteriome was significantly distinct between groups, and significant inter-kingdom interactions were documented. Bergeyella zoohelcum was identified as a potential biomarker of a healthy feline oral microbiome. These data suggest that fungi might play a role in the etiology and pathogenesis of FCGS, and that oral health should not simply be regarded as the absence of microbial infections. Instead, it may be viewed as the biological interactions between bacterial and fungal populations that coexist to preserve a complex equilibrium in the microenvironment of the mouth. Additional investigations are needed to improve our understanding of the feline oral ecosystem and the potential interactions between viruses, bacteria, and fungi in FCGS.

Stem cell therapy prior to full-mouth tooth extraction lacks substantial clinical efficacy in cats affected by chronic gingivostomatitis

OBJECTIVES

The aim of this pilot study was to determine the safety, efficacy and immunomodulatory function of systemically administered adipose-derived mesenchymal stem cells (ASCs) in cats affected by feline chronic gingivostomatitis (FCGS) prior to full-mouth tooth extractions.

METHODS

Five client-owned cats affected with FCGS that did not undergo full-mouth tooth extractions for FCGS treatment received two intravenous injections of 20 million fresh, allogeneic or autologous ASCs. An oral examination with photographs, a complete blood count, blood immune cell phenotyping and a biochemical profile were completed at 0 and 6 months after treatment.

RESULTS

Four cats completed the study and one cat exited the study 3 months after treatment. While the treatment was determined to be clinically safe, no positive clinical response was observed in three cats and a mild response was noted in two cats. Furthermore, none of the cats exhibited immune modulation, as evidenced by no alteration in circulating CD8+ T cells, normalization of the CD4:CD8 ratio or neutrophil counts.

CONCLUSIONS AND RELEVANCE

Unlike the reported efficacy of ASCs in treating cats with non-responsive FCGS after full-mouth tooth extraction, the systemic administration of ASCs prior to full-mouth tooth extraction lacks substantial clinical efficacy and is not recommended at this time.