- Mainly large and giant dog breeds, especially with stocky conformations
- Seen in cattle - Herefords
- Subluxation of hip joint due to maldevelopment
- Not present at bith
- Inherited + environmental factor involvement (nutrition, exercise)
- Pelvic muscles are behind the bone development in rapidly growing dogs -> lack of restraint of the joint -> excess movement before acetabulum is fully mature
- Usually develops within first 6 months of life
- Varying degrees of severity
- Pathogenesis:
- Joint laxity / acetabular dysplasia
- -> Flattened femoral head +/- mild or severe periarticular osteophyte formation
- -> Thickening of femoral head + degeneration of articular cartilage
- Eburnation
- Predisposes to DJD
- Round ligament of femoral head may rupture -> luxation