A four year-old intact male Dalmatian was referred to the veterinary teaching hospital at Louisiana State University for acute, non-weight-bearing left hindlimb lameness of three weeks duration. Information supplied by the referring veterinarian indicated the lameness was first diagnosed and treated seven months previously, but recurred three weeks ago. External rotation of the left stifle, mild discomfort upon stifle flexion, mild to moderate muscle atrophy and palpable joint effusion were noted during physical examination. Slight cranial drawer movement with a soft end-point was discovered during manipulation of the left stifle. A triangular bone fragment and thickened, confluent intracapsular soft tissues were observed on radiographs of the stifle. Radiographically, moderate degenerative changes suggested chronicity. This report describes the clinical and radiographic findings of a rarely reported partial avulsion of the origin of the cranial cruciate ligament in a skeletally mature dog.