Sign Five
He gets up in stages
He used to stand in one movement. Now there is a sequence. Front end first, a pause, then the back end, sometimes with a shuffle of the hind feet to get them underneath him. The first few steps are stiff, and then he walks it off and looks entirely normal, which is the part that makes owners dismiss it.
What it usually is. Arthritis. This is the textbook presentation, and the fact that it improves with movement is not reassurance. It is the diagnosis. Inflamed joints stiffen at rest and loosen with use, which is why the worst moment of an arthritic dog's day is the first minute of it, and why a vet examining him at two in the afternoon may see nothing at all.
What it can also be. Cold and damp make it worse, so a dog who is stiff in November and fine in July has not recovered. He has had an easier month. Weakness without stiffness, where the back legs simply fail to hold rather than hurting, points somewhere else and needs a proper look.
What to do. Film it. This is the single most useful thing an owner can hand a vet, and almost nobody does it. Thirty seconds of your dog getting up from a cold floor first thing in the morning carries more information than any description of the same event, and it removes the problem of a dog who performs perfectly in the consulting room.