A well trained hog dog is no more threat to the deer than a bird dog. Look at the alternative, you can either trap (or try to) the hogs or let them ruin your deer hunting area. They will eat all the acorns and other foods available for the deer and move on. I don't think you can trap all of them, they are smart creatures. A hog jump dog and a couple of catch dogs will make a big dent in their populations. Just make sure the hog hunter take all of the hogs away from the property. The presence of a few trained dogs occasionally on the property won't run the deer away, but the hogs eating the food sources will.