All right someone had to think the life jacket was funny besides me.
I really did duck hunt with a guy that put life jackets on his labs. He said if the gators grabbed a swimming dog they would pull it under to drown it but the life jacket would pull them up. The gator would get tired and give up
Not sure if it was true or not because we were duck hunting in the cold and I don't think the gators are very active then. Maybe the handle on top makes it easier to pick them up out of the water.
But if the dog just sinks then it might really work. But I will still laugh at the whole situation. If it was my dog I would laugh.
Fat floats so the leaner dog will tend to sink. Also lung capacity or how much air is in the lungs. If the dogs exhails it will sink easier. I am not sure how you teach a dog to keep air in his lungs.
Seriously I would put a dog life jacket on the dog. Put the dog in the water so he can learn to swim. After he can get around in the water with the life jacket take it off and see if he swims. If he still sinks I would come up with some kind of tough life jacket. You don't want a hog running into the water and your dog drowns.