Are the other dogs intact?
Maybe talk to your neighbors and see if they will have a "puppy playdate" and let all of your dogs socialize. Our neighbors have a bird dog, a min-pin, and a rat terrier. The min-pin thought we were the end of the world, but then we had a puppy socialization with both of our neighbors, and no problems since! It also is helpful, since we are 3 big ranchs, if any of the dogs get loose they end up at one of our houses to play
we've had the bird dog (lab mix I think, but really well trained) show up at our porch begging for treats