Retrospective evaluation of a hand-sewn side-to-side intestinal anastomosis technique in dogs and cats.

Background: Hand-sewn intestinal resection and anastomosis are commonly performed in veterinary medicine. The outcome of the hand-sewn side-to-side anastomosis (SSA) technique has never been described and compared to other techniques in dogs and cats. Aim: The study aims to describe the side-to-side hand-sewn anastomosis technique in small animals and to compare it with the end-to-end technique. Methods: A retrospective evaluation of the clinical records of dogs and cats that underwent enterectomy between 2000 and 2020 and were treated with side-to-side or end-to-end anastomosis (EEA) was performed. Results: Of the 52 dogs and 16 cats included in the study, 19 dogs and 6 cats received an SSA, and the remaining received an EEA. No intraoperative complication was reported. However, short-term complication rates were comparable, and mortality rates in the EEA group were higher. At the same time, stenosis was a frequent complication of SSA and was never reported following EEA. Conclusion: End-to-end technique remains the gold standard for hand-sewn intestinal anastomosis in small animals. However, SSA can be considered for selected cases with acceptable morbidity and mortality rates.

Case report: Sublingual mucinosis in a dog.

A 11-month-old male intact Shar-Pei (26. 5 kg) was presented for a bilateral sublingual swelling of 4 months duration. The exploration of the oral cavity highlighted the presence of bilateral sublingual swellings, primarily consistent with bilateral ranula. The bilateral disease was treated with two subsequent surgeries 4 weeks apart. During the surgery, after removing an elliptical portion of the mucosa of the sublingual swelling, the presence of gelatinous tissue was visualized, and no saliva was present. The result of histological exam was oral mucinosis. At the subsequent follow-up the dog was in excellent conditions, without any symptoms. 1 month after the last operation, the dog underwent a visit in sedation to better evaluate the oral cavity. Both surgical sites were well-healed and without the presence of relapses. Upon 8 months follow-up the patient remained free of disease. This is the first reported case of oral mucinosis in sublingual mucosa in dogs. In this case the surgical treatment was curative.

Validation of oral brushing as a non-invasive technique for the identification of feline oral squamous cell carcinoma by DNA methylation and TP53 mutation analysis.

Feline oral squamous cell carcinoma (FOSCC) is a frequent and progressively invasive tumour. Early lesions are difficult to recognize based on the sole clinical examination and may be misinterpreted as non-neoplastic. Mutations of TP53 and epigenetic alterations of specific genes are present in FOSCC and may be early detected. Aim of this prospective study was to investigate the DNA methylation pattern of a 17-gene panel and TP53 mutational status of FOSCC cytological samples obtained by oral brushing. Results were compared with a control group, in order to validate this non-invasive procedure for the screening of FOSCC. In FOSCC, the same analyses were carried out on the corresponding histological sample, if available. Thirty-five FOSCC and 60 controls were included. Mutations of TP53 were detected in 17 FOSCC brushings (48%) and in none of the controls (P < .001). Six genes (ZAP70, FLI1, MiR124-1, KIF1A, MAGEC2 and MiR363) were differentially methylated in FOSCC and were included in a methylation score. An algorithm based on TP53 mutational status and methylation score allowed to differentiate FOSCC from controls with a 69% sensitivity and a 97% specificity (accuracy, 86%). In 19 FOSCC histological samples, TP53 mutational status was fully concordant with brushings and a positive methylation score was observed in all cases. These results are promising for the identification of FOSCC by oral brushing, although some factors may limit the accuracy of this technique and further studies are required to assess its reproducibility in clinical practice.

Analysis of DNA methylation and TP53 mutational status for differentiating feline oral squamous cell carcinoma from non-neoplastic mucosa: A preliminary study.

Feline oral squamous cell carcinoma (FOSCC) is characterized by high local invasiveness and early bone lysis. The late diagnosis largely limits the efficacy of therapy and increases treatment-related morbidity. The aim of this exploratory study was to assess the methylation pattern of 10 candidate genes and TP53 mutational status in histologic samples of FOSCC. Results were compared with normal oral mucosa and oral inflammatory lesions, in order to establish a gene panel for FOSCC detection. For 10 cats, the above analyses were also performed on oral brushing samples, in order to explore the utility of these methods for screening purposes. Thirty-one FOSCC, 25 chronic inflammatory lesions and 12 controls were included. TP53 mutations were significantly more frequent in the FOSCC (68%) than in the non-neoplastic oral mucosa (3%; P <.001). Based on lasso regression analysis, a step-wise algorithm including TP53, FLI1, MiR124-1, KIF1A and MAGEC2 was proposed. The algorithm allowed to differentiate FOSCC with 94% sensitivity and 100% specificity (accuracy, 97%). When applying the proposed algorithm on 10 brushing samples, accuracy decreased to 80%. These results indicate that the altered DNA methylation of specific genes is present in FOSCC, together with a significant proportion of TP53 mutations. Such alterations are infrequent in normal oral mucosa and chronic stomatitis in cats, suggesting their involvement in feline oral carcinogenesis and their utility as diagnostic biomarkers. Further studies on a high number of brushing samples will be needed to assess the utility of a screening test for the early detection of FOSCC.

Assessment of PDGFRß promoter methylation in canine osteosarcoma using methylation-sensitive high-resolution melting analysis.

Platelet-derived growth factor signalling pathways play a fundamental role in inducing and sustaining the proliferative and prosurvival stimuli in canine osteosarcomas (cOSAs). The increased expression of platelet-derived growth factor receptors (PDGFRs) α and ß, and their cognate ligands, were almost invariably observed in cOSAs and OSA-derived cell lines. In particular, overexpression of PDGFRß-mediated signalling pathways was found in both the tumour microenvironment, where it drives stromal cell recruitment, and in neoangiogenesis, such as in tumour cells where it triggers aberrant proliferation, migration and local invasion. The majority of the pathological consequences of PDGFRß signalling are because of aberrant expression. In fact, epigenetic dysregulation of oncogenes throughout demethylation of their promoter has emerged as a pivotal mechanism driving oncogenesis. The aim of this study was to assess the methylation status of the PDGFRß promoter and to clarify its role in modulating the expression of the tyrosine kinase receptor in canine osteosarcoma. The CpG island of the PDGFRß promoter was identified using a mixed in silico and experimental approach, and a method based upon the methylation-sensitive high-resolution melting assay for quantitatively and precisely assessing the methylation status of the promoter was then set up. The method herein described was then exploited to assess the methylation status of the promoter in a case series of cOSAa. COSAs consistently but variably expressed PDGFRß. However, the promoter was almost completely demethylated, and its methylation status did not correlate with the expression levels. This finding supported the hypothesis that post-transcriptional regulatory mechanisms may act in cOSAs.

Prevalence of p53 dysregulations in feline oral squamous cell carcinoma and non-neoplastic oral mucosa.

Squamous cell carcinoma is the most common malignant oral tumor in cats. The late presentation is one of the factors contributing to the detrimental prognosis of this disease. The immunohistochemical expression of the p53 tumor suppressor protein has been reported in 24% to 65% of feline oral squamous cell carcinomas, but no study has systematically evaluated in this tumor the presence of p53 encoding gene (TP53) mutations. The aim of this retrospective study was to determine whether p53 immunohistochemistry accurately reflects the mutational status of the TP53 gene in feline oral squamous cell carcinoma. Additionally, the prevalence of p53 dysregulation in feline oral squamous cell carcinoma was compared with that of feline non-neoplastic oral mucosa, in order to investigate the relevance of these dysregulations in cancer development. The association between p53 dysregulations and exposure to environmental tobacco smoke and tumor characteristics was further assessed. Twenty-six incisional biopsies of oral squamous cell carcinomas and 10 cases each of lingual eosinophilic granuloma, chronic gingivostomatitis and normal oral mucosa were included in the study. Eighteen squamous cell carcinomas (69%) expressed p53 and 18 had mutations in exons 5-8 of TP53. The agreement between immunohistochemistry and mutation analysis was 77%. None of non-neoplastic oral mucosa samples had a positive immunohistochemical staining, while one case each of eosinophilic granuloma and chronic gingivostomatitis harbored TP53 mutations. Unlike previously hypothesized, p53 dysregulations were not associated with exposure to environmental tobacco smoke. These results suggest an important role of p53 in feline oral tumorigenesis. Additionally, the immunohistochemical detection of p53 expression appears to reflect the presence of TP53 mutations in the majority of cases. It remains to be determined if the screening for p53 dysregulations, alone or in association with other markers, can eventually contribute to the early detection of this devastating disease.

Aloe barbadensis miller versus silver sulfadiazine creams for wound healing by secondary intention in dogs and cats: A randomized controlled study.

The objective of this study was to compare the effectiveness of the topical application of Aloe barbadensis Miller (juice and fresh gel) to skin wounds, in dogs and cats, with that of topically applied silver sulfadiazine cream. The sample included 16 patients with cutaneous wounds (13 dogs and three cats) that were divided into three groups. Aloe vera "juice" and "fresh gel" were applied for groups I and II, respectively, while silver sulfadiazine was applied for the control group III. In order to evaluate the healing of wounds, the following parameters were taken into consideration: the percentage of wound shrinkage, the healing time and the macroscopic appearance of the scarring process. The interpretation of the data relating to the percentage of wound shrinkage showed a faster rate for groups I and II compared to that of group III. However, the wound shrinkage rates between "juice" and "fresh gel" protocols were not significantly different. Aloe vera was more effective than silver sulfadiazine, in accelerating wound shrinkage, reducing healing time and decreasing the severity of the associated injuries.