An investigation into risk factors for bilateral canine cruciate ligament rupture.

OBJECTIVES: To investigate the incidence of bilateral cranial cruciate ligament (CrCL) rupture and determine any associated risk factors.
METHODS: The patient information system and surgical database at the Queen Mother Hospital for Animals, Royal Veterinary College, were searched from March 1998 to March 2007. Patient files were reviewed and data recorded. The risk factors considered included: gender, neuter status, breed, body mass, age and concurrent orthopaedic disease.
RESULTS: In total, 511 dogs were identified as having cruciate rupture and included for analysis. Bilateral rupture of the CrCl was present in 38.7% (198/511) of the dogs. The mean (± SD) time that passed until the contralateral CrCL ruptured was 57.9 weeks (± 54.1; range 3 to 260 weeks). Dogs with bilateral cruciate rupture were younger (mean ± SD; 4.3 ± 2.7 years) than dogs with unilateral cruciate rupture (mean ± SD; 5.3 ± 2.8 years). In dogs with CrCL rupture, male dogs were more likely to have bilateral rupture than female dogs, overweight dogs were more likely to have bilateral rupture, Golden Retrievers were less likely to have bilateral rupture, and Rottweilers had the highest odds of bilateral rupture. CLINICAL SIGNIFICANCE: In dogs with CrCL rupture, this study suggests possible relationships towards the incidence of a bilateral rupture also occurring as more likely in male dogs, young dogs with a mean age of four years (4.3 ± 2.7 years), Rottweiler dogs, and with an average elapsed time between ruptures of 57.9 weeks.