Outcome and complications associated with correction of pectus excavatum using external coaptation in cats less than 20 weeks of age: 25 cases (2010-2024).

OBJECTIVE: To evaluate clinical and radiographic outcomes in cats with congenital pectus excavatum (PE) treated with external coaptation and to identify associations between clinical presentation, defect severity, and postoperative complications. STUDY DESIGN: Retrospective clinical study. SAMPLE POPULATION: A total of 25 cats. METHODS: Medical records from 2010 to 2024 from a small animal referral hospital were retrospectively evaluated for cats undergoing sternal splinting for PE. RESULTS: A total of 25 cats met inclusion criteria. All cats were younger than 20 weeks of age. Most cats (19/25) presented with tachypnea or exercise intolerance, and 25/25 had a palpable defect on examination. The survival rate was 24/25. Significant improvement in conformation was observed postoperatively, with frontosagittal index decreasing from a mean of 5.44-2.09 (p < .001) and vertebral index increasing from 4.45-8.47 (p < .001). Clinical signs resolved in all cases by recheck. Complications included pneumothorax, suture breakage, dermatitis, persistent defect, and death. No association was found between preoperative severity and breed, pneumothorax, or suture breakage. Splint duration was for a median of 28 days (range: 21-43 days) and was significantly inversely associated with dermatitis severity (p = .036). CONCLUSION: Congenital PE in this population of cats 20 weeks of age or younger was corrected with external coaptation, resolving clinical signs and improving thoracic conformation with minimal complications. CLINICAL SIGNIFICANCE: External coaptation is an effective correction method for PE in young cats, resulting in resolution of clinical signs. While the survival rate in this study was excellent, owners should be counseled on potential complications.