Chuck, it wasn't the dog. As a few have said and I believe it also that ground nestng birds start to loose some of their scent close to egg producing time. All game birds like quail, pheasants and turkeys,(includes ducks, geese) the hens won't sit on the eggs until the last egg is laid so that they will all hatch around the same time, so I do believe that it is nature helping out.
Fawns have no scent at all when first born, within a day though they are keeping up with mom, but she will make them lay down to thwart off danger.
Two weeks ago I let out a few quail that I had left, first the males were picking on each other, then the hens were doing the same. Let them out and the only one that stayed around was a cock. Every time I let the dog out he would look for that quail and most of the time he found him, sometimes around the pen or in the hay field. The last week no bird, didn't hear him calling, nothing. The other day let the dog out does his same thing, looks for birds and the rabbit that lives under the shed, I see him on point but it isn't as intense as on the quail, I go over with my flushing stick and beat the grass and a young starling comes out flying low, before I could tell him to stay he is after it and the thing lands on the ground screaming, so I go and pick it up and naturally it grabs my finger with it's beak. I take it and put it away from him and tell him no.
Hated to make this so long, but some young birds do have scent and I know the cock quail do. The day after I let the quail out it had rained during the night, I went out to work in my garden and I see him in the hay field, I figure he is doing his business, well he was on point. I walked back to the house to get my flushing stick and when I caught up to him, I walked in carefully and a hen quail flushed and then I saw the cock still on the ground. He found the hen again so I quess she still had scent.
Maybe it's only when they are in the process of laying eggs.