
I think the owner has misunderstood the procedure of how the x-rays are taken.
The legs are pulled straight and rotated, if the hips were dislocated the dog would have a terrible score as a dislocated hip would score 53 per hip.
The procedure notes here:
http://www.bva.co.uk/public/chs/HD_PNs_2008.pdf explain things.
3.2 Positioning
A standard position for radiography must be employed. Accordingly:
(a) the dog should be placed on its back with the pelvis in the middle of the cassette and the x-ray beam centred on
the midline between the hips (ie the centring point should be at the level of the cranial edge of the pubis);
(b) in order to avoid rotation, the head and body should be supported in a straight line by a cradle or by blocks at
the thorax. Tilting of any part of the dog's body is likely to cause axial rotation of the pelvis and asymmetry of
the hips;
(c) the hind legs should be FULLY extended and adducted so that the femora lie parallel to each other and parallel
to the film;
(d) the legs should be inwardly rotated so that the patellae lie centrally in the trochlear grooves;
(e) suitable ties or tape should be used to achieve correct adduction and inward rotation; poor positioning which
allows either lateral or longitudinal tilt of the pelvis may prevent accurate radiological assessment of the hips;
(f) if the radiograph shows axial rotation of the pelvis, this may be corrected by raising the hip on the side on which
the image of the obturator foramen is smaller.