Though we have hunting spaniels in the house with our four birds, we provide supervision and training. No dog is allowed in any room where a bird is free. And even when caged, no dog will be left alone with a bird. This has avoided a tragedy. Just the same, here is why dogs and birds will never make a trustworthy team.
Dogs are predators.
They hunt mostly by smell, but movement attracts their attention and stimulates the hunt. Birds, as all of you probably have noticed, like moving. In fact, they make quick rapid moves, the most inviting type of movement. To a dog this is as good as waving a flag in front of a bull. While dogs have never had the reputation for killing birds that cats have, they also have never really had the opportunity, until birds are brought into the house.