Neoadjuvant intralesional triamcinolone is not associated with increased incidence of surgical site complications in dogs with cutaneous and subcutaneous mast cell tumors

Objective: The objective of this study was to determine the incidence of postoperative incisional complications following excision of cutaneous and subcutaneous mast cell tumors (MCTs) in dogs receiving neoadjuvant intralesional triamcinolone (NIT) within 30 days of surgery. Methods: Retrospective study of dogs undergoing MCT excision at a tertiary referral hospital from January 2018 to February 2026. Inclusion required histologically confirmed MCT, NIT within 30 days of surgery, and sufficient medical record documentation for outcome assessment. Tumor- and treatment-related variables were recorded. Surgical site complications (SSCs) within 30 days of excision were classified as major or minor. Associations between variables and SSCs were evaluated with nonparametric tests and mixed-effect logistic regression. Results: 69 dogs with 78 MCTs were included. Overall SSC incidence was 25% (20 of 78 MCTs; 95% CI, 16.4% to 36.8%), with 90% classified as minor. Surgical site complication incidence was significantly decreased in tumors receiving ≥ 2 injections compared with those receiving a single injection (0% vs 36%). No association was identified between SSC and triamcinolone dose, timing of injection relative to surgery, tumor characteristics, perioperative medications, or bandaging practices. Among tumors with a recorded response, 65% decreased in size, with a median reduction of 40%. Conclusions: NIT administration within 30 days of excision was not associated with an increased incidence of short-term postoperative incisional complications in dogs with cutaneous or subcutaneous MCTs. Clinical Relevance: NIT may be considered as an adjunct in management of canine MCTs to reduce tumor size and peritumoral inflammation while maintaining an acceptable SSC rate.