I have never had luck with skid plates staying on. Maybe you have to buy more than the $9 version.
What are you looking for the vest to do? Just provide some protection to the dogs underside? I've used this one from Cabelas with good success.
http://www.cabelas.com/cabelas/en/t...parentType=index&indexId=cat601233&hasJS=true
I'd be careful with the neoprene vests in warm conditions. I also have a K-9 Skid Plate vest. They are quite popular and provide more protection than the Cabelas vest.
http://www.gundogsonline.com/dog-vest/k-9-skid-plate.html