Boyd,I had similiar concerns about it with how my Westie would act, but he is leaving it alone. What you want to do is put up any cords, get rid of big floor clutter and turn it loose when you and the dogs leave the house.It is good the first couple of times to watch it to figure out if anything is a hazzard to it. If it sucks up a sock for instance, it will stop and say Uh Oh Uh Oh and blink a red light. If you don't turn it off and remove the sock, it will shut its self off and wait for your help.
I find myself doing a lot more cleaning now that I have a helper. I sweep under things that are too low for it to go under and sweep them out where it will pick them up. It picks up so much dust, I now dust my books etc.. knowing it will come along and sweep up the dust.
If you have to keep an extension cord on the floor, then do what I did and cover it with heavy clear tape. Then it will sail right over the tape rather than sucking up the cord.
I can't tell you how great it is not to drag out the big old vaccum which really didn't pick up all that my dirt dog does. I think its because it sweeps as the brushes spin it into the dirt tray.
You have to clean the brushes underneath every so often but for some reason I don't mind it. It feels like you are caring for a friend.