it has become more noticeable in the last 6 months, where his back legs will suddenly "give way".
He doesn't seem to be in any discomfort, and he still enjoys a walk, I suspect moving around helps his condition.
Regarding weight, he is by no means overweight, I would estimate around 25-30 kg
He appears to drag his back legs a bit, and sometimes they almost "give way", but he still enjoys a walk, and can get around.
It has deteriorated over the last 9 months or so, we assume it may be an arthritic condition.
He has been seen by vets when he has had innoculations, and they just say it is his age.
As for weight, I would say around 25kg