There are several threads here on BYC regarding breeds of dogs that are good w/poultry, you might do a search for a couple of those. I've seen pictures here of all kinda breeds doing excellent with poultry and great with predator control. To some extent, it is the dog poop I think that deters other small dog like creatures, not a fierce animal patrolling the grounds. Maltese is NOT what you want, fox might eat them! And your friend is right about greyhound, they would love to chase your birds as well as probably the foxes. Think about what the breed was bred and raised for when you are making your choice. There is a book called the ASPCA guide to dogs that might be helpful to you right now, and it is usually at the library.
We foster for the humane society and the anatolian shepherd we had here was the one that I would have recommended for you of the 100 or so dogs we have had exposed to the chickens. He was very self-possessed and did not need much attention and stayed here without a fence, the very first day. But did you catch that number of dogs I had to choose from that would have been perfect for you right off the bat? One out of 100 and no one at the humane society could possibly have known which one to tell you to get as Anatoleans are not always like him, if you were going that route. You might do better looking for a breeder of these types of dogs and ask for one they are retiring from breeding as you don't have the time to raise a pup. Older dogs are SO much easier and puppies are overrated. They might let you have one inexpensively because they don't need her and would want her to get a good home. Just make sure you are not at a puppy mill! Go to a local dog show to find a breeder or ask your vet, do not go through Craigs list or pet stores.
Most of the humane society discards are dogs about a year old that didn't turn out for their owners. So I'd be real careful going the purchased puppy or humane society year-old dog route in your situation unless you are going to have a year off to be home to train it, lol. Don't we all wish!
Dogs get less needy generally as they get older (unless they are a golden retriever lol). Or look into a rescue of the breed you choose and tell them your needs. PM me if you intend to go that route as that is my real expertise, not chickens! Or if you are going to the humane society, I could send you a list of what to NOT look for, which is probably the most important thing, not getting the wrong dog.
I have friends with heelers (australian cattle dogs) and often you will see a border collie good with livestock but there are exceptions of course and they are perhaps more a size you would find less intimidating. Both of those breeds require a close relationship with their person so you might reevaluate how much you might desire to have a wonderful new friend who always loves you, always is happy to see you, never nags, always wants to go with you and always wants to play. They are dirty, messy and sometimes gross, but ....things wash. To me dogs are very much worth it. But they are a huge time-suck and money pit and installing electric fence would be a lot less maintaince-free as there are tons of start-up costs to becoming a dog owner, the financial investment is probably a wash.
I'd research breeds right now as foresight and knowledge makes the best dog owners....go forewarned! It is almost more like there would be a zillion dogs to avoid out there for your situation but a few gems, you'd have to just find the right one, or train one to become the right one. Usually, it is the latter, not the former.
