I´ve really enjoyed reading all the comments here. I have six dogs and a good number of poultry. the 3 small dogs can´t be trusted, I never let them anywhere near my birds. They´re Poodle x Pincher, Yorkie, and Maltese. All terrier-based. When they were younger they got chased off by a broodyhen. Great. But they slowly learned that not all chickens are broody and most of them are great to chase or kill. I put up chain-link around the garden area where I keep the little dogs and sometimes a neighbour´s chick gets through....life expectancy zero.
My other 3 dogs are bigger, mongrelst hat needed a home, plenty of those around here...I got them at 4 weeks (mother abandoned them) and 7 weeks of age. They were reared together with the chickens. All good. At 7 months of age they started to kill the chickens. Only when we went out. Then when we were home, but not close-by. They didn´t always get killed, sometimes I caught them red-handed and beat them, but it didn´t really help long-term. I didn´t know what to do. Re-homing dogs here is very difficult, as there are so many abandoned on the roads already...I read all sorts of stuff to help,but nothing seemed quite reliable..having 3 made it more difficult, as one eggs the other on. I believe it was play gone mad...one poor hen turkey had to be destroyed, was too badly injured. Another pullet was just mouthed to death, etc. So, the 3 bigger dogs were separated from the birds, went into the garden area with the others .Two months passed. I let them out with the chickens again, supervised, bit by bit. The birds have a metre-high fence to separate them from the dogs. The dogs could get over if they really wanted, but they don´t.Only one bird comes over the top. I think it was just the running, flapping thing that got them excited. The dogs have a very large yard to run in and the birds have separate, very large areas to scratch about in. When we´re home we let the chickens scratch about in the yard together with the dogs to keep the pest population down. And now all is OK with the full-grown chickens etc, I leave them out there together for hours when I´m around, but they can´t be trusted still with the chicks. I have to keep chicks protected, so they only get out free when we´re nearby. There´s one indian-type hen that regularly flies over into the dogs´area whether we´re in or out, and they don´t take any notice. When she was small, one of the dogs got her and licked her until she was sopping.. Frightened her to death, now she doesn´t go near them, but they leave her well alone now. The geese "beak" the dogs so the dogs stay out of the way. The muscovies tend to fly,my favourite muscovy hen was killed by a dog in mid-flight. Bitten in the chest, died immediately, dogs didn´t touch her, just sat around wondering what to do. Dead duck "attacked" 3 dogs. No idea if it helped, but they´ve not touched another since, so the dogs have just learned to differenciate (a loud "no") between my ducks and anything else around (they chase guan, carcará, vultures, etc).
As far as my 3 go, I´ve no idea what they are. The mother looks shepherd x corgi, the father looks pitbull x lab. A real mix. But knowing the breed´s purpose will help. I´ve read some posts that refer to "bird-dog", but it depends if the breed is for retrieving (retrieves), or pointing (points), or flushing (like spaniel breeds), or whatever. And then you´ll get those that will simply let you down! I have friends who have dachsies, they´ve tried to keep chickens, but....kill in a flash. They´re a ground-hunting breed......but you always get the exceptions. While I´ve been writing this, there´s been a cockerel wandering around tin the yard, the dogs have ignored it. They´re just over a year old now, full of energy, but seem to be learning...here´s hoping!