He sounds like he's just a doddery old man enjoying life

There is a new medicine on the Market called Yumove ( yes, spelling is correct ) .it is a supplement so can be given as well as medication from a vet. It has the usual glucosamine but from natural source of green lip mussels. Codliver oil, starflower oil and other natural products. It has good reports up to now.
I use the skin soothing alternative, Yumega ( also correct spelling

) for itchy dogs. It has resulted in some dogs not needing medication any more.
They both smell of fish oils so most dogs love it on their meal.
Maybe worth a try.