...what is causing the problem without tests, but it shouldn't hurt to start him on some otc joint medication whenever you like.

There are 4 that I like...glucosamine, chondroitin, MSM, & CBD oil.

To decide when to put mine on such items, I go by several things...age, size, injuries, symptoms, and athleticism.

It doesn't work as well with the oldest dogs, or the worst joint problems, but I've still seen a marked improvement in quality of life, depending on the dog. And, there can he an improvement in the joint when given earlier.

He may well have been playing. Silly boy! :-)