My 10 year old corgi gets along great with my four 6 month old bantams. She was introduced to them when they were 1 day old and told, "off". She happily tolerates them and even runs out to help them when she hears the alarm call.
I wouldn't get rid of the dog just yet. Sounds like it can be trained. Let the chickens out to free range while dog is on the leash.
Each time the dog seems like it's staring at a chicken, redirect by yanking on the chain and say "NO" in a low, mean voice.
Keep doing that, and the dog will look elsewhere.
Next, sit or stand with your leashed dog and throw out some scratch, calling the chickens over. Let the chickens get close. Each time the dog even "looks" at the chickens, yank the leash and say "NO". Make sure the dog sits quietly with the chickens right there.
Always praise him for looking the other way. Give him a little milk bone after he tolerates the chickens eating nearby if he doesn't lunge at them.
After the dog gets used to that, let him off the leash while the chickens free range. Keep his attention giving him a milk bone every few minutes. Walk around the yard with the bones so he'll follow you.
If he does run after the chickens, get him, grab his snout with one hand, push him onto his side with the other. Make him stay on his side on the ground keeping his head pressed hard against the ground....saying NO the entire 30 seconds. That's how dominate dogs teach the young ones.
This will take many days, maybe weeks.
Depending on the dog, it may NEVER work.
ALWAYS supervise your dog until you feel completely comfortable.
I have raised 3 Golden Retrievers with my method and they protect and love the chickens, never harming them.
Cleo is a rescue we got at 15 months, and is now almost 4. Cleo was introduced to chicks about 18 months ago and now herds and disciplines them as needed. Bad rooster gets a *time out*with Cleo escorting him to the yard and keeping him there a few minutes. She will also guard against him attacking people. She is fine with the hens. She also does head counts in the coop to make sure everyone is there.
The chickens free range over about 1.5 acres. We don't have close neighbors.
Cleo's intelligence is incredible. If she were to attack anyone or anything, I would first ask why, because she would have a reason that is logical.
My dog is a Border Collie mix and she has no problem with the chickens. She's mostly an outdoor dog (her choice). We had her for years before getting chickens so didn't know how she would react. She could care less about them, unless she wants to play, then she runs thru the flock scattering chickens everywhere...it's so funny and sometimes chase them around the yard, but not trying to catch them. The girls get their exercise..hehe. My dog has never tried to hurt them. They will share the dog bed and dog house together too on cold days. I suppose just see what your dogs interest level is with them. If it seems obsessed with checking them out behind a fence, then I would be a little "iffy" to let them together. If your dog is like "eh, whatever", then you may be fine. But know, there is always a risk of any dog to suddenly injure or kill a chicken, no matter what their personality (rule of thumb...if they have teeth...they could bite).
Took a little time to make her understand that the chickens are MINE!, but my German Shepherd is now a great watch/guard dog. Once she understood who "owns" them it was easy. She now looks forward to all the tasty treats they leave for her. The treats that come out the back end of the chickens.
My cocker got to my 3 chicks at about 3 weeks, He killed one and the other two were mauled and in shock. (They survived) I don't think he meant to kill the one but it happened. I watch him closely with the chickens and every now and then he gets that look but has never harmed them again. The chickens have pecked at him and if he acts like he wants to chase them I tell him to leave it in a stern voice and he will leave off. Neither of my two cockers are especially or well behaved obediance dogs but I am not afraid of them being outside if the chickens are out too. I just never trust Zephy fully around the chickens.
I had my flock with my 2 big dogs. One a catahoula/australian shepherd, one a blue tick hound. Both have killed cats. Neither bothered my chickens. My neighbors dogs killed my chickens. 15 in all over the summer. I no longer let mine free range, but on the community I live on there is another free range flock and my dog still leaves them alone. In fact, the cutest thing is that Louie(my hound) will sit braying at squirrels, not five feet from the free range chickens, and he begs for bread while I feed the chickens.
I have 3 dogs and they all run togeather in the yard with the chickens. Never have killed one but they did take out a neighbors duck that flew over the fence.