Once a dog gets the taste for chicken its near impossible to get them over it... Our dog, German Shep/ Retriever was a great dog, he loved us, our Grandkids and was an awsome watchdog, but we found out one day as we were wondering why our chickens had quit laying that he also loved fresh eggs, he would sneak under a fence, over a fence, thru a fence, how ever he could and steal the eggs, always crafty, never leaving evidence til one day I caight him with an egg in his mouth... We added another fence line to give the chickens more protection and gave the dog a time out with a stern warning... less than six months later two of my very best laying hens mysteriously showed up dead, after the second one died I asked hubby if it could possibly be the dog, he said no way, probably a racoon or something else.. A few days later he came up to the house to tell me that in fact it was the dog killing the chickens, asking him how he knew it for sure he said that he caught the blasted dog with a hen in his mouth... Hen survived the ordeal, dog went to a new home without small critters that can be used as chew toys..
We also raise rabbits and have to much time and money invested into our little farm to always be worried about losing it all to a dog that cannot help but do what his instincts tell him too.