Temperament wise, I would recommend collie, Smooth or rough, McNab, or English shepherd. All smart, biddable (thus easier to train) breeds that tend to be more protective of livestock than aggressive to it. Giant schnauzer is also a possible choice, they are protective of their people, the minis are really more like terriers, which will go after chickens. Generally speaking, avoid all terrier breeds for that reason. Bird dog breeds are going to be likely to be interested in the chickens, but should NOT have a killer instinct, they are bred (and trained) to not damage the retrieved bodies. They are not generally good watchdogs or predator deterrent, except they will bark, as most dogs would. Swiss Mt dogs are short coated, and may be better allergy wise. Not so uncommon anymore, but pricy, and cancer prone. Temperament generally good. So many choices, as well as mixes of any type, this could go on and on. Allergy wise, it's not the coat, it's the dander. Every breed has different dander, so you will have to be around individuals of your chosen breed first. However, a short coated breed that is easy to bathe regularly, may be your best bet. I've worked as a dog groomer for many years and I am really allergic to Irish Setters. Hives, hay fever and asthma within minutes! But if I put them straight into the tub first, I can be around them all day with no problem.