It does not seem that the chickens are going to be Things Great Danes Eat.
As you can see, Charley is not a huge threat to our new poultry friends. Judging from this photo, I think the predominant thought that runs through Charley's head at any given time is "What exactly are you going to throw at me today and how am I best going to circumnavigate it?" Or in the alternative, "You have got to be freaking kidding me."
Ivy wants to lick the chickens. One of them got a little wet because of her, and let me tell you, the phrase "mad as a wet hen" was not first uttered for no reason.
Milo wants to poke the chickens with his giant nose. That seems to be his thing. Poking smaller animals. And nobody wants to be poked. So that may be a problem, but at least it's our biggest problem.