Dogs try to play and herd the chickens.

[dainerra]

as Sourland said, your chiweenie is teaching your Pyr to chase the animals. For every time you allow bad behavior to happen, you set back training at least a month. In this case, you also have to bear in mind how a trained LGD would punish the chiweenie for chasing poultry. I can guarantee that even a non-aggressive rebuke cold possibly kill him, send him to the vet at a minimum.

 

[Contrary]

If you continue to allow the little dogs to harass the chickens, there is no way you can realistically expect the Pyr to not join in the fun. Control your little dogs and allow the Pyr to do his job.

Especially since the little dog is considered "off limits."

 

[TheJadeChicken]

Yes, I understand what you all are saying. I am not exactly sure where to start. I want to get the little ones to stop. I actually have about 4 dogs to work with, the Chiweenie, 2 Chihuahuas, and a Dachshund. One of the Chihuahuas and the dachshund are not mine and they will not listen to me. But it is mostly the Chiweenie that starts the chasing. I am thinking if I get him to stop, then the others might follow.

 

[dainerra]

contain and manage. dog doesn't go out the door unless it is on a leash.
if you have a problem with the dog slipping out, then baby gates to make sure the dog doesn't have access to the door (or crate the dog or shut it in another room when the door is going to be open).

at this point, the dog might not be able to be trusted, ever. in that case, you are just going to have to contain and manage the situation.
Even one time of getting to chase the chickens is going to be a huge setback in the training. So make sure that everyone in the house is on the same page in making sure to contain the dog.