Use of unbiased metagenomic and transcriptomic analyses to investigate the association between feline calicivirus and feline chronic gingivostomatitis in domestic cats.

OBJECTIVE: To identify associations between microbes and host genes in cats with feline chronic gingivostomatitis (FCGS), a debilitating inflammatory oral mucosal disease with no known cause, compared with healthy cats and cats with periodontitis (control cats). ANIMALS: 19 control cats and 23 cats with FCGS. PROCEDURES: At least 1 caudal oral mucosal swab specimen was obtained from each cat. Each specimen underwent unbiased metatranscriptomic next-generation RNA sequencing (mNGS). Filtered mNGS reads were aligned to all known genetic sequences from all organisms and to the cat transcriptome. The relative abundances of microbial and host gene read alignments were compared between FCGS-affected cats and control cats and between FCGS-affected cats that did and did not clinically respond to primary treatment. Assembled feline calicivirus (FCV) genomes were compared with reverse transcription PCR (RT-PCR) primers commonly used to identify FCV. RESULTS: The only microbe strongly associated with FCGS was FCV, which was detected in 21 of 23 FCGS-affected cats but no control cats. Problematic base pair mismatches were identified between the assembled FCV genomes and RT-PCR primers. Puma feline foamy virus was detected in 9 of 13 FCGS-affected cats that were refractory to treatment and 5 healthy cats but was not detected in FCGS-affected cats that responded to tooth extractions. The most differentially expressed genes in FCGS-affected cats were those associated with antiviral activity. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that FCGS pathogenesis has a viral component. Many FCV strains may yield false-negative results on RT-PCR-based assays. Coinfection of FCGS-affected cats with FCV and puma feline foamy virus may adversely affect response to treatment.

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.

A multicenter experience using adipose-derived mesenchymal stem cell therapy for cats with chronic, non-responsive gingivostomatitis.

BACKGROUND: The ability of mesenchymal stem cells (MSCs) to modulate immune responses inspired a series of clinical trials addressing oral mucosal inflammation. We previously reported on the safety and efficacy of fresh, allogeneic and autologous, adipose-derived mesenchymal stem cells (ASCs) to treat feline gingivostomatitis (FCGS), an oral mucosal inflammatory disease that shares similarities with human oral lichen planus. METHODS: To meet clinical demand and goals for future commercialization, we determined the feasibility of shipping fresh ASCs to distant clinics and extended our pilot studies to expand safety and efficacy data for shipped and non-shipped ASCs in a cohort of 18 FCGS cats enrolled locally and at a few different locations within the USA. RESULTS: We found that ASCs retained their viability, phenotype, and function after shipment. ASCs administered systemically resulted in a 72% positive response rate, identical to that noted in our previous studies. Cats that responded to ASC therapy had a significant decrease in circulating globulin concentration and histological evidence of decreased CD3+ T cells and CD20+ B cells in the oral mucosa. Responder cats also had significantly decreased percentages of CD8lo cells in blood prior to and at 3 months post-ASC therapy. CD8lo cells may serve as a potential "predictor" for response to systemic ASC therapy. CONCLUSION: Fresh feline ASCs can be successfully shipped and administered to cats with FCGS. ASCs modulate the immune response and demonstrate efficacy for chronic oral mucosal inflammatory lesions that are characterized by CD8+ T cell inflammation and T cell activation. FCGS is a potentially useful naturally occurring large animal model of human oral inflammatory diseases.

Radiographic outcome of root canal treatment of canine teeth in cats: 32 cases (1998-2016).

OBJECTIVE To describe the radiographic outcome of root canal treatment (RCT) of canine teeth of cats. DESIGN Retrospective case series. ANIMALS 32 cats with 37 canine teeth with complicated crown fractures that underwent RCT. PROCEDURES Medical record databases of 5 referral veterinary hospitals were searched to identify cats that underwent RCT between 1998 and 2016. Only cats that had at least 1 follow-up examination during which radiographs were obtained of the treated canine tooth or teeth were included in the study. Dental radiographs obtained before and immediately after RCT and during all follow-up examinations were reviewed. Treatment was considered successful if the periodontal ligament space was within reference limits and preoperative external inflammatory root resorption (EIRR), if present, had stabilized. Treatment was considered to have no evidence of failure if preoperative EIRR had stabilized and preexisting periapical lucency was stable or decreased in size but had not resolved. Treatment was considered to have failed if periapical lucency or EIRR developed subsequent to RCT or preexisting periapical lucency increased in size or preoperative EIRR progressed following RCT. RESULTS Follow-up time after RCT ranged from 3 to 72 months. The RCT was successful for 18 (49%) of the 37 treated teeth, had no evidence of failure for 12 (32%), and failed for 7 (19%). Preexisting EIRR and patient age ≥ 5 years significantly increased the rate of RCT failure. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that RCT was a viable treatment option to salvage endodontically diseased canine teeth in cats.

Osteonecrosis of the Jaws in Dogs in Previously Irradiated Fields: 13 Cases (1989-2014).

The aim of this report was to characterize osteonecrosis of the jaws (ONJ) in previously irradiated fields in dogs that underwent radiotherapy (RT) for oral tumors. Osteoradionecrosis of the jaw (ORNJ) was further defined as osteonecrosis in a previously irradiated field in the absence of a tumor. Thirteen dogs clinically diagnosed with 15 ONJ lesions were included in this retrospective case series. Medical records were reviewed for: breed, sex, weight, and age of the patient, tumor type, location in the oral cavity and size, location of the ONJ, time from RT to ONJ onset, known duration of the ONJ, and tumor presence. Where available, histological assessment of tissues obtained from the primary tumor, and tissues obtained from the ONJ lesion, was performed, and computed tomographic (CT) images and dental radiographs were reviewed. RT and other treatment details were also reviewed. Twelve dogs developed ONJ in the area of the previously irradiated tumor or the jaw closest to the irradiated mucosal tumor. Recurrence of neoplasia was evident at the time of ONJ diagnosis in five dogs. Time from RT start to ONJ onset varied from 2 to 44 months. In three cases, ORNJ developed after dental extractions in the irradiated field. Dental radiographs mostly revealed a moth-eaten pattern of bone loss, CT mostly revealed osteolysis, and histopathology was consistent with osteonecrosis. To conclude, development of ONJ/ORNJ following RT is a rare, but potentially fatal complication. Patients undergoing RT may benefit from a comprehensive oral and dental examination and treatment prior to RT.

Non-Radiation-Related Osteonecrosis of the Jaws in Dogs: 14 Cases (1996-2014).

Osteonecrosis of the jaws (ONJ) is an entity of major clinical impact characterized by chronically exposed necrotic mandibular or maxillary bone. Its clinicopathological characteristics and possible inciting or risk factors are well described in humans but only anecdotally reported in dogs. Treatment modalities and outcome vary depending on the inciting factors involved and the extent and severity of the lesions. The objectives of this study were to retrospectively describe the clinicopathological features of non-radiation-related ONJ in a series of 14 dogs, identify possible inciting or risk factors, and report on the surgical treatment and outcome. For all patients, the medical records were used to collect information regarding signalment, clinical signs, characteristics of the oral, jaw and dental lesions, diagnostic imaging findings, histopathological and microbiological analysis, treatment performed, and outcome. The data collected showed that non-radiation-related ONJ appears to be an infrequent clinical entity but of significant impact in dogs; that a history of systemic antibiotics and dental disease is common among affected dogs; that previous dental extractions are commonly associated with ONJ sites; that using a systematic diagnostic approach is essential for diagnosis; and that thorough surgical debridement combined with a course of oral antibiotics was effective in the described dogs affected by advanced non-radiation-related ONJ.

Dental radiographic findings in cats with chronic gingivostomatitis (2002-2012).

OBJECTIVE: To compare dental radiographic findings in cats with and without feline chronic gingivostomatitis (FCGS). DESIGN: Retrospective case-control study. ANIMALS: 101 cats with FCGS (cases) and 101 cats with other oral diseases (controls). PROCEDURES: Controls were age- and treatment date-matched with cases. Conventional full-mouth dental radiographic views were evaluated for distribution, pattern, and severity of alveolar bone loss (periodontitis), tooth resorption, buccal bone expansion, tooth fractures, and retained roots. RESULTS: All cases and 77 (76%) controls had periodontitis; differences in extent and severity of periodontitis were significant, with semigeneralized or generalized and moderate or severe periodontitis in 78 (77%) and 93 (92%) cases, respectively, and 28 (28%) and 38 (38%) controls, respectively. The pattern of alveolar bone loss in cases was dominated by horizontal bone loss, with a nonsignificant increase in vertical bone loss, compared with that of controls. Cases were more likely than controls to have external inflammatory root resorption (49 [49%] vs 25 [25%]) and retained roots (57 [56%] vs 28 [28%]). Fewer dental fractures occurred in cases (14 [14%]) than in controls (35 [35%]). There were no differences between cases and controls in breed, sex, or presence of feline resorptive lesions or buccal bone expansion. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that FCGS was associated with more widely distributed and severe periodontitis, with a higher prevalence of external inflammatory root resorption and retained roots than other oral diseases. Full-mouth radiographic views are indicated for cats with FCGS to diagnose the extent of associated periodontitis, reveal external inflammatory root resorption, and identify retained roots.

Efficacy of cyclosporine for chronic, refractory stomatitis in cats: A randomized, placebo-controlled, double-blinded clinical study.

Sixteen cats with chronic stomatitis, that had previously undergone premolar-molar or full-mouth extractions, were randomly assigned a group to receive 2.5 mg/kg cyclosporine or placebo orally twice daily Neither the clinician nor the clients were aware of the group assignments. Cats were evaluated prior to treatment and every 2 weeks for 6 weeks using a 30 point Stomatitis Disease Activity Index (SDAI) score. Mean improvement in SDAI scores among cats in the treatment group after 6 weeks was 52.7 %. This was significantty diffrent fom the mean improvement (12.2 %) of cats in the placebo group. During the 6 week study period, 7 of the 9 cats in the treatment group (77.8 %) showed a > 40 % improvement in SDAI score, while 1 of 7 cats in placebo group (14.3 %) showed a > 40 % improvement in SDAI score. This difference was statistically significant. Individual variability in the absorption of orally-administered cyclosporine was high. Trough whole-blood cyclosporine levels ranged firm 32.1 ng/ml to 1,576.2 ng/ml. At the end of the 6 week observation period, there was a statistically significant diference among cats with trough whole-blood cyclosporine levels >300 ng/ml (72.3 % improvement) compared with cats with cyclosporine levels < 300 ng/ml (28.2 % improvement). Whole-blood cyclosporine levels > 300 ng/ml were associated with significant improvement in oral inflammation in cats with chronic stomatitis that had previously undergone premolar-molar or fuill-mouth extraction.

Oral inflammation in small animals.

The oral cavity can be affected by a wide variety of disorders characterized by inflammation of the gingiva and/or oral mucosa. In dogs and cats, differential diagnoses for generalized oral inflammatory disorders include plaque-reactive mucositis, chronic gingivostomatitis, eosinophilic granuloma complex, pemphigus and pemphigoid disorders, erythema multiforme, and systemic lupus erythematosus. In addition, endodontic or periodontal abscesses, infectious conditions, reactive lesions, and neoplastic conditions may initially present with localized or generalized inflammation of the oral mucosa. Determination of the underlying cause of an oral inflammatory condition relies on a thorough history, complete physical and oral examination, and incisional biopsy and histopathologic examination of lesions.

Outcome of surgical endodontic treatment in dogs: 15 cases (1995-2011).

OBJECTIVE: To document the short- and long-term outcomes of surgical endodontic treatment in dogs in a clinical setting. DESIGN: Retrospective case series. ANIMALS: 15 dogs that underwent surgical endodontic treatment. PROCEDURES: Medical records of dogs that underwent surgical endodontic treatment at 3 institutions from January 1995 to December 2011 were reviewed. Information extracted included signalment, history, initial clinical signs, physical and radiographic examination findings, treatment, and outcome. Outcome was determined through evaluation of the pre- and postoperative radiographs as well as clinical and radiographic findings at follow-up evaluations. On the basis of radiographic findings, treatment was considered successful if the periapical lesion and bone defect created by surgery had completely healed and no new root resorption was detected; a treatment was considered to have no evidence of failure if the periapical lesion remained the same or had not completely resolved and root resorption was static. RESULTS: 15 dogs were treated by means of apicoectomy and retrograde filling following a failed or complicated orthograde root canal treatment. The mean long-term follow-up time was 15.2 months (range, 3 to 50 months). On radiographic evaluation, 10 of 15 dogs had successful resolution of the periapical disease; 5 dogs had no radiographic evidence of failure of endodontic treatment. All dogs were considered to have a successful clinical outcome. CONCLUSIONS AND CLINICAL RELEVANCE: Surgical endodontic treatment was an effective option for salvaging endodontically diseased but periodontally healthy teeth of dogs in which orthograde treatment was unsuccessful and nonsurgical retreatment was unlikely to succeed.