https://www.ebay.com/itm/TENS-Unit-M...-/142666390485 I've used a few of these in the past (not this brand in particular but the therapy) and I have one I use still. I am a paraplegic and some muscles are very difficult to exercise. It is a big help and at this price it does not hurt to try. Simply shave the area that you plan on treating and follow some directions or tips from some well known sport therapists online. Also I am not sure about your hound's diet but some good B12 shots would also help. The swimming pool as the gentleman stated above would be an excellent first choice but if you cannot get to one then the elec. stimulator is good. Blessings