There are other causes of back pain and hind limb weakness that must be differentiated from lumbo-sacral disease. Thus, if your dog has back pain, your veterinarian will try to localize the pain to a specific segment of the spinal cord. Although diseases of the spinal cord above the lumbo-sacral region may produce hind leg weakness, spinal pain should be evident when the spine in front of the pelvis is manipulated during a neurological examination. With lumbo-sacral disease, the pain is elicited when the spine at the pelvis is manipulated. The effect on the hind legs should be quite different also when there is disease of the spinal cord.
Hip dysplasia and ruptured cruciate ligaments within both knees can produce a clumsy hind leg gait. Hip dysplasia can produce pain on hip extension, which may be misinterpreted for lower spinal pain. But neither disease should produce neurological abnormalities, such as knuckling of the feet or urinary or fecal incontinence.
Metabolic diseases can produce hind leg weakness but will usually be associated with other clinical signs and blood work abnormalities.
Degenerative myelopathy is a slow progressive neurological disease that occurs most commonly in German shepherd dogs. Hind leg reflexes are usually quite different to those found in dogs with lumbo-sacral disease and the disorder is not associated with pain.