We have four children (oldest is almost 16, youngest is 6), two large labs, 6 cats, and well, the guinea pigs don't count.....there was many a year that the tree was in a playpen (from Goodwill- it was for the tree, not the kids). Finally, the tree is out, but "boxed in" a corner by furniture. We have no breakable decorations below tail level (used to be hand level, too, but I am hoping our youngest is beyond that now!).....so far, so good. In 18 years of marriage we haven't "lost" a tree yet- a few expendable ornaments and a few tipping incidents (usually surrounding kittens), but so far, so good (knock on superstitious wood here).
Don't sweat it too much. We have grown to dearly love our "child/dog/cat friendly" tree. Went to the "Festival of Trees" here in town (a local fundraiser), and admired all the designer trees. When I think about it, I wouldn't trade my homemade by chubby hands ornaments or lopsided tree for the world. When all are grown and gone, maybe I will have that "Disney" tree....until then, we just try and keep it upright!!!!