Epidemiology of orthopaedic conditions in companion animals with emphasis on cranial cruciate ligament disease ; Epidemiologiske aspekt ved ortopediske smådyrsjukdomar med fokus på korsbandskadar

Lameness caused by orthopaedic disease is an important reason for owners to take their dog or cat to the veterinarian. Many diagnoses, such as cranial cruciate ligament disease (CCLD), considered the most common cause of hindlimb lameness in dogs, usually require expensive and complicated surgical interventions. Information regarding risk factors and treatment methods influencing disease outcome is consequently relevant for both pet owners and veterinarians. Although various studies had assessed the pathophysiology, epidemiology and treatment outcome of CCLD in dogs when this thesis was initiated, knowledge about inherent risk factors for development of the disease was limited. Moreover, there was a paucity of information regarding breed susceptibility for orthopaedic diseases in Norway and Sweden, and the scientific literature concerning CCLD in cats was sparse. The overall aim of this thesis was to expand the understanding of orthopaedic diseases in dogs and cats, in particular related to breed susceptibility and risk factors with a potential influence on the prognosis of CCLD. To reach this aim, retrospective data from medical records at two university animal hospitals, the Norwegian University of Life Sciences and the Swedish University of Agricultural Science, were utilised, in addition to owner questionnaires and data from the national pet ID-registers. Firstly, a case-control study was performed to estimate breed susceptibility for common surgically treated orthopaedic conditions in popular Norwegian and Swedish dog breeds. The Labrador retriever, Rottweiler, German shepherd dog and Staffordshire bull terrier were identified to have increased risk of elbow dysplasia compared to mixed breed dogs. Susceptibility for CCLD was found for the Rottweiler, but not the Labrador retriever, although this breed has commonly been regarded as predisposed. The Chihuahua was the only breed with increased risk of medial patellar luxation. In the second study, characteristics and long-term outcome of CCLD were described in ...