Disease-related and overall survival in dogs with cranial cruciate ligament disease, a historical cohort study

Objective: To analyse the effect of treatment method and other risk factors on survival in dogs with cranial cruciate ligament disease (CCLD). Methods: A historical cohort study of 333 dogs presenting with CCLD at two University Hospitals (2011-2016) was performed. Signalment, history, treatment and follow-up details were retrieved from medical records, dog owners and referring veterinarians. Treatment groups were defined; conservative or surgical with either lateral fabellotibial suture (LFS) or osteotomy procedures. Multivariable Cox proportional hazards models were applied to evaluate risk factors for disease-related and overall survival. Results: Sixty-five dogs were conservatively managed, 125 treated with LFS and 143 with osteotomy techniques. At follow-up (autumn 2018), 164 dogs (49.3 %) were alive and 169 (50.7 %) were dead. Both final Cox proportional hazards models included variables for treatment, age, weight and hospital. In addition, the final disease-related model included a variable for orthopaedic comorbidity, while non-orthopaedic comorbidities and a time-varying effect for age on a linear scale were included in the overall survival model. Treatment method was found to have an effect on both disease-related and overall survival and surgical treatment was associated with a lower hazard than conservative treatment. Conclusion: Survival in dogs with CCLD is influenced by treatment strategy, comorbidities, age and weight.