I agree with electric fencing to keep the dog seperated from the chickens , but they can be trained to actually be penned in with the chickens for predator protection if you want to take the time to do it .
Buy a radio controlled electronic training collar . They have become very reasonable in price and can be adjusted down to a very mild shock that is feels more like an electric vibrator on my bare skin ; up to a pretty good but harmless jolt for those more hard-headed type dogs .
Next lead the dog through your flock WITHOUT the training collar . Make sure there is no rooster or broody hen around that will attack the dog . If he shows interest in chasing or grabbing for a chicken give him a quick tug to bring him to a stop while at the same time saying " NO " in a firm but emotionless voice . Do not let him move again untill he is not focussed on the chicken . Praise him with words and petting for going past a chicken andd ignoring it . Its important that the session does not end untill he has passed a chicken without getting excited . Do this every other day for a week . Give him a treat AFTER every session .
On the second week place the electronic training collar on the dog with it adjusted to a very mild shock and repeat the walk through the flock . This will be another every other day week . On the first day if he does show interest in chasing a chicken say " NO " as you hit the shock button . If it does not get his attention , turn the power up and resume the training session . On the next session if he does happen to continue to show any desire to chase or grab , shock him without saying anything as you do it . { I like to talk to my dogs , I might say something like " You know better " AFTER they are reprimanded } Most dogs have already learned even before the start of the second week that chasing chickens is not allowed , but bull-headed dogs or those with a high prey drive will now learn that there are consequencees for wrong behavior . You should be able to " shoo " the chickens away from you without the dog wanting to chase . Again , praise him every time he passes through the chickens without misbehaving and after the session ends give the dog a treat . Most dogs will be consistantly ignoring chickens long before the end of the second week .
Third week put the training collar on , enter the pens , then turn the dog loose . Ignore the dog and feed the chickens some scratch , and then reward the dog with a treat if it ignores the flock . Have that collar turned up enough that it is going to get attention , this should already have been done in the other sessions . Any misbehavior on his part should be addressed with an immediate shock . On the next training session put him in with the chickens and stay out of the pens yourself . { I'm sure you know by now what to do if he shows interest in chasing chickens
. } You might want to get a chair and make these sessions an hour or so , even hide behind a tree or something during these sessions . If the dog has his own kennel run , during this week you might take a calm chicken to his run and set it down to be with the dog for a training session .
For those who cannot stand the idea of using the training collar , forcing the dog to the ground and pinning it there for a minute or two in place of the shock can be used instead . However many dogs will then figure out that its you [ not the mysterious shock ] once he's seperated from you and is free to do as he pleases ............. Almost any dog will start to actually guard the chickens as " his/hers " after these three weeks , making it worth the time in my opinion .