A. The pain you describe might be a result of hip dysplasia or arthritis. Visit your veterinarian as soon as possible; meanwhile, limit your dog's activity to low-impact leash walks.
Lower spinal or back pain may be caused by instability between individual vertebrae. Certain conformations and abnormalities, such as degeneration of disks that act as shock absorbers, predispose dogs to this weakness. Swelling and forming of scar tissue put pressure on the spinal cord and its nerves.
I recommend X-rays of the lower spine, pelvis and hips. Your veterinarian might suggest additional X-rays or tests. With today's diagnostic techniques, new surgical options and lots of love, your dog can return to comfortable living..