Luxation and dislocation are roughly the same term when discussing joints.
So subluxation and partial dislocation would be analogous as well. The
most common cause of subluxation of the hip joint in young dogs is hip
dysplasia. It is sometimes possible to identify the subluxation as early
as 3 to 4 months of age with X-rays. It can take up to two years for there
to be clear evidence of subluxation sufficient to diagnose hip dysplasia
although the great majority of dogs with this problem show signs much earlier.
In dogs with moderate subluxation, it is often possible to surgically alter
the hip socket so that the luxation is corrected and reasonably normal
hip function returned, using a procedure known as a triple pelvic osteotomy.
This procedure requires considerable orthopedic surgical skill and equipment
and is often done at referral centers and veterinary hospitals in the United
States, rather than at a general practitioner's facility. It is also possible
to replace the hip joint. In large breed dogs this can be done at an early
age due to their size. Both of these procedures are expensive enough that
many owners find themselves in the position of having to consider euthanasia
when the problem is severe and funds for surgical repair low. There are
some other causes of abnormal development of the hips. Infection with Neospora
caninum causes muscular atrophy sufficient to prevent normal development
of the hip joints in some dogs. Trauma can do this and there are probably
other causes.