I realize that many of us, use our dogs for things besides "decoying".But if I could build a perfect "decoy dog", right now this is where I would start.
I like a decoy dog to range a few hundred yards,(any where out to a mile depending on terrain) come back to "check in", then leave out again.
I want a dog to "yo-yo" a coyote till it is shot, or quits the game.
If a yote hangs up, I want the dog to go to them, and tease them back to me.If a yote leaves the country, I want the dog to follow "aways", but not chase it to Canada.
If the dog is at the calling stand, I don't want them to close to me,or other hunters, because I feel the dog does draw attention.
I want them to find cripples, catch or bay, is fine with me.
I think size does matter,although the big dogs can and do decoy some aggressive yotes, many times the yotes will hang up and just bark at the dog, while the dog is trying to tease them in, then run off.Smaller dogs, the yotes tend to be "braver".
The size I like is 50 to 60#'s.
Big dogs are effected more by heat,big bone,and lots of muscle, makes the big dogs slower, they also tend to get sore more than the smaller dogs.Besides that they eat more.
I don't want my decoy dogs chasing any livestock,when we are hunting.
Most of the time I use two dogs, in the late winter and spring, and summer. In the fall I most times use one dog.
Color is not so important to me,depending on where I am hunting, any dog from full black to full white, could be easy to see, or dam near invisible.
I like more of a hotnose dog, just enough nose to find a coyote, but not so much they wanna take a 3 hr old track.
Since my first dog, my ideas have changed, I have made lots of mistakes(and still do) my ideas I'm sure will change again, as I learn.
Duane