I wouldnt have a dog with only bull and whippet in them because I dont think the whippet has the frame to carry the bull weight as opposed to the bull grey. I like a racier dog about 23-25, and have a bull/whip/grey.Some bull whippets look to heavy for me.But im sure bull/whippets have no problem doing teeth. If your only retrieving a few charlie a week I think a bull/greys over kill, the bull/whip/greys Ive seen and mates have worked have been better rabbiting dogs and catchers being that bit lighter and agile.