"An inherited neurological disease, called Neuronal Degeneration or NDG, has been reported in Great Pyrenees dogs. The age-of-onset of this disease is very young, well before an affected dog's first birthday, but begins quite mildly. Initial signs include slipping, sliding, and difficulty maneuvering on smooth surfaces. The gait is abnormal - the dog may seem weak, clumsy, or uncoordinated. Over time, these problems progress and worsen. The abnormalities are most pronounced in the hind limbs, and both sides of the body tend to be affected symmetrically. Eventually, affected dogs display a wide-base stance, become unable to negotiate stairs, have a generalized loss of control and coordination over body movements, and may experience intermittent falling. The condition itself is non-painful, although stumbling and falling can obviously cause pain and traumatic injuries. Necropsy of the neurological system reveals pathological changes throughout (in the brain, spinal cord, and peripheral nerves). The disease will continue to progress until the dog may not be able to support its own weight or walk on its own. Research carried out at the University of Minnesota indicates that this disease is inherited in an autosomal recessive manner. We have identified a mutation within a disease-associated gene, and all affected dogs have two copies of this mutation. We are now offering a genetic test which allows owners to determine their dog?s status for this mutation in order to diagnose affected dogs and to guide future breeding decisions." [From University of MN]