We've had whippets for about 40 years and find them to be the greatest, the gentlest, the sweetest, and the most beautiful dogs I know. My son has just lost one that he's had for 14 years and we are all mourning. But a Parkinson dog needs special training and there is one place in Chadds Ford, PA. They are trained to step on your foot when you freeze prompting you to move; they also hold fast when you lose your balance. The president of our support group recently lost a Great Dane and he is getting another next month. He will go to Chadds Ford for 2-3 weeks to bond with the dog before bringing him home. I do not remember the name of the kennel off-hand but they do have a web site. I suspect that the yellow lab is probably more common for this kind of specialized training. Best of luck, Michel