[anonymous]

Do you have pet health insurance? If so, and your vet prescribes aqua therapy (otherwise known as swimming in a heated pool) it may be covered.
See if there is a veterinary clinic near you that offers these services.
Just 20 minutes twice a week might make a big difference https://www.vetinfo.com/aquatic-therapy-for-dogs.html

Also, most supplements are not necessary and a waste of money….
Discuss with your vet