The epidemiology of stifle joint disease in dogs with a focus on cranial cruciate ligament disease

Stifle joint disease (SJD) is common in dogs and comprises many diagnoses, of which cruciate ligament disease (CLD) is often reported as the most prevalent. Several treatment options are available for CLD, but there is no consensus on which treatment yields the best results. The aims of this thesis were to investigate the epidemiology of SJD in dogs, with a focus on CLD, and to evaluate outcomes in dogs after treatment for CLD. Data from Agria Pet Insurance was used to evaluate risk factors for SJD and CLD. The diseases affected breeds of all sizes, although larger breeds, especially molosser types, were overrepresented among those at high risk of CLD. An association between breed size and age at CLD diagnosis was observed: most breeds diagnosed at younger ages were large or giant, while most that were older at diagnosis were small. Seven large breeds also had an increased risk of euthanasia due to CLD. Outcome assessments after treatment for CLD included evaluation of severe postoperative complications and survival in dogs diagnosed with CLD at two university animal hospitals. Severe postoperative complications occurred in 25.1% of surgically treated stifles. Stifles treated with tibial plateau levelling osteotomy had a significantly lower hazard of severe postoperative complications than those treated with lateral fabellotibial suture. The hazard also decreased with increasing age and increased with increasing body weight. The median survival from treatment initiation to CLD-related euthanasia was 1.3 years. Dogs treated with osteotomy procedures had a significantly lower hazard of CLD-related euthanasia than conservatively treated dogs. The hazard increased with increasing age and body weight, and was higher for dogs with concurrent orthopaedic comorbidities