Latest Data to the Genetics of Canine Hip Dysplasia : A Review of Literature
Canine hip dysplasia is a developmental orthopaedic disorder and was first described by Schnelle in 1935 (35). Hip dysplasia is a polygenic and polyfactorial disorder characterized by instability of the coxofemoral joint leading to secondary degenerative joint disease. Secondary changes are caused by abnormal wearing of the bone surfaces, and can result in acetabular bone sclerosis, osteophytosis, thickened femoral neck, capsule fibrosis and subluxation or luxation of the femoral head. The resulting osteoarthritis is irreversible, thus the only way to improve the welfare of susceptible breeds is through genetic selection. Many studies have confirmed that hip dysplasia has a polygenetic hereditary aetiology, conditioned by environmental factors. Amount of physical exercise, weight gain, growth rate, breed and nutrition are some factors that will influence the expression of the disease. The aim of this literature review is to highlight the characteristics and latest research within this field. I will discuss the genetic background, breed predisposition and clinical appearance. I will also discuss the diagnosis, treatment and prevention. In addition to this I will also discuss the work of the Norwegian Kennel Club. The hip screening program organized by the Norwegian Kennel Club implies standardized evaluation and recording of radiographic hip status, and the grading is done according to the protocol of the Fédération Cynologique Internationale (FCI).