My dog is almost 13 years old and suffers from arthritis and various conditions that cause her problems using her back legs. So I took her for an evaluation at a pet rehab center near me. After several sessions she got to go into the doggie hot tub for a swim. The doctor and an attendant (in wet suits) took her into what I believe must be a swim spa. The water was probably about 80 degrees so not to overheat the animals. She was able to move her back legs and actually swim around the spa.
I am going to find out more details about how they sanitize the water because I can't imagine all the hair and stuff that must accumulate in that spa!! Amazingly, the water was crystal clear! and my poor baby really enjoyed her swim.