The 2-tier grading system identifies canine cutaneous and/or subcutaneous mast cell tumors with aggressive biological behavior regardless of growth model.

Histologic grading of canine cutaneous mast cell tumors (cMCTs) has prognostic and therapeutic implications, yet validation for subcutaneous MCTs (scMCTs) is lacking. For scMCTs with or without dermal invasion, determining their biological behavior remains poorly standardized and sometimes sparks controversy. This prospective study aimed to assess the prognostic utility of the 2-tier histologic grading system in MCTs with different growth models (GMs) and explore the prognostic impact of the GM itself. We assessed 6 histologic GM categories: solely cMCT (C-SC0), cMCT with superficial (C-SC1) or deep subcutaneous (C-SC2) involvement, solely scMCT (SC-C0), and scMCT with deep (SC-C1) or superficial (SC-C2) infiltration of the dermis. Ninety-one MCTs from 76 dogs undergoing excision and regional/sentinel lymphadenectomy were examined. GM classification identified 11 (12%) C-SC0 tumors, 12 (13%) C-SC1, 15 (16%) C-SC2, 21 (23%) SC-C0, 15 (16%) SC-C1, and 17 (19%) SC-C2. Mitotic count, 2-tier grade, nodal involvement, surgical margins, and outcome were stratified according to GM. scMCTs lacking dermal invasion, historically associated with a benign clinical course, had a poor prognosis in 10% of cases. cMCTs exhibiting deep subcutaneous involvement included the largest percentage of high-grade tumors (33%), had the highest occurrence of overt nodal metastases (33%), and had the lowest 1-year survival rate (86%). Histologic grade was confirmed as a relevant prognostic factor, surpassing nodal involvement and histologic margin status. The 2-tier histologic grading enabled the identification of all MCTs with aggressive biological behavior, regardless of their cutaneous or subcutaneous location.

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.

Perforated duodenal ulcer in a dog with gallbladder agenesis.

Background: Duodenal ulceration (DU) in dogs derives from different causes but has never previously been related to gallbladder agenesis (GA). GA is a rare congenital disorder in dogs and is considered a predisposing factor for DU in humans. Case Description: A 5-month-old intact female Maltese was presented for acute vomiting and diarrhea. Abdominal ultrasound suggested duodenal perforation and absence of the gallbladder. Exploratory laparotomy was performed to treat the perforation and confirmed GA. Hepatic ductal plate malformation (DPM) was histologically diagnosed in liver biopsy, but no signs of liver dysfunction were detected by blood work at first admission. Two months later, the dog developed signs of portal hypertension and medical treatment was started. However, the clinical condition gradually worsened until liver failure and the dog was euthanized 8 months after surgery. Necropsy confirmed hepatic abnormalities. Conclusion: This report describes a case of DU associated with GA and DPM in a dog. As in humans, GA may represent a hepatobiliary disease predisposing to gastroduodenal ulcerations.