Older dog suddenly behaving like a naughty puppy

[SunnySkiesSleepsintheMorning]

He’s always been a good, non destructive dog. In recent weeks, he’s become destructive with his stuff and with ours. He does respond to being told no but he never used to try this. He’s ruined cushions, scratching sofa and destroying toys.

I think he’s in pain, would it manifest like this? He has arthritis and was on anti inflammatory medication for a long time but he kept getting diarrhoea. Vet suggested something different (non anti inflammatory) and I’m wondering if it doesn’t work as well. We trialled him reducing the anti inflammatory a few years ago and it was obvious that he needed it because he was reluctant to go on walks. Now, he’s happy enough for walks but clearly agitated.

Any ideas please?

As it's so out of character I'd take him back to the vet. He may well be in pain

Is he currently on medication? I am not clear from your post. Our last dog had arthritis, and we tried some new medication from the vet instead of his regular stuff and he became hyperactive and puppy like, which was strange for an old gentleman. I took him back to the vet and we took him off it. I was told it was one of the recognised side effects. Sadly I can't remember the name, which is not helpful, but I did google it and answers said the same thing as my vet had about it. Was not helpful for an old stiff dog to suddenly start leaping around on the furniture and belting up and down the stairs.

Sorry, yes he is on this new medication and has been for a couple of months. I will look up the side effects and phone for a vet appt.

Is he on Tramadol? That can have heavy duty side effects.
Is he old enough for dementia to be a possibility?
Can you get a pen for when he's not being supervised to keep him (and the house!) safe?

No, he’s on flexadin. He’s only 9, I hope it’s not Dementia. :(
Strangely enough, he seems more relaxed when he’s on his own. Maybe he’s gone off us!

That sounds rather young for dementia. I don't know that drug. Any chance he's feeling better than he has for years? I hope the vet can help.

I'd take him back to the vets. Meds could be making him a little hyperactive. Only other thing I can think of is could he be understimulated? I'm sure you've had broken limbs or something and experienced to frustration of being restless and bored but unable to physically do anything about it. If he can't exercise like he used to due to arthritis but still has that mental energy, maybe it's frustration. Perhaps a job or game to do? Teach him tricks that engage him mentally?

The dog walker says he’s spritely, playful and happier than ever with her. Maybe he is feeling better and needs some more stimulation? I pay with him quite a bit but maybe he needs more mental stimulation.

He’s always been a tricky one to read. I never quite know when he’s in pain or not and he never loses his appetite.