Pectus excavatum is a rare congenital malformation which occurs in humans and many domestic animal species. This case report documents an atypical presentation of pectus excavatum in a dog in which right ventricular outflow obstruction was present. Cardiovascular compromise has been documented in humans with pectus excavatum, however, to our knowledge, there is only one report of cardiovascular abnormalities associated with pectus excavatum a dog. Pectus excavatum in the dog of the present reportwas treated with sternal splint placement. Sternal sutures were passed in a manner that best allowed for the avoidance of cardiac laceration through a caudal to cranial placement of sutures with ventral retraction of the sternum. The patient became clinically normal after treatment. No signs of pectus excavatum were evident on post-splinting radiographs and follow up echocardiogram revealed no cardiac abnormalities.