Be Careful With Pets
We would not say that cats won't try to attack chickens as they will be a novelty to the cat who will want to investigate but once they've been pecked and flapped at by the angry hen, they usually won't try to do it again! Hens can be pretty formidable when they feel threatened and will flap their wings violently and peck at noses and faces of anything trying to attack them and that is enough to scare off most cats. Bantams may be at risk from injury if attacked by a large cat though. Some dogs, on the other hand, will attack and kill chickens so I'd always advise caution where dogs are concerned. If you have aggressive cats and are worried for the hens safety, they would be perfectly happy in the Eglu run all day, if necessary.
Regarding dogs, we think it really depends on the breed but we always encourage chicken keepers to err on the side of caution, particularly with hunting dogs, as they can be unpredictable, no matter how well trained they are. We have heard of several cases where family pets have caught and killed free ranging chickens when the hunting instinct has become too strong. The hens are perfectly safe within the run so if you are in any doubt, let them stay there in safety. Alternatively, only let the hens free range when you are around to supervise them fully to prevent any accidents.