Good morning
You’re at a difficult stage – which is very hard.
Yes, there is more you can try but focusing on pain meds may not be your target.
if he is bright loving life and not adverse to handling of all parts of him, plus willing for his joint to be gently manipulated then adding further meds may not be the right direction.
Prednisolone is a steroid which I assume he’s on for with gut, skin or autoimmune issues?
These meds are quite tissue wasting in the long term – is he at his lowest effective dose – could you chat with your vet regarding whether it is essential in your management plan?
Gabapentin is called a voltage gated calcium channel blocker which influences over active nerve firing so aims to reduce inappropriate/ excessive nerve firing of pain signals – this can be very effective but can also leave weak older dogs very flat and wobble which can lead to them being discouraged from moving… it is worth discussing this with your vet.
I would strongly suggest doing a blood sample if your dog is on diuretics and ACE inhibitors fir his heart – especially with steroids as well – that may show an electrolyte imbalance that could be adding to his weakness.
I would suggest if he is bring by with a lot of zest for life discussing the case with a physio or hydrotherapist as he may not need pain relief but needs attention to maximise his remaining strength and stamina.
I would make sure his weight is as good as you can get it – BCS 4/9 would be ideal.
I would definitely put all the home management in place to make sure his movement around the house is safe – i.e. rugs and runners and everywhere easy access.
I would look at him wearing a support harness so you can support him when getting to a stand and walking – this will help dramatically and help him restore some strength xxx
Let us know how you get on
Hannah x