Yeah, I find the designs which employ animals to allow someone to cause them to walk over certain features and effectively make the house impenetrable for future invasions pretty frustrating. It is what I'd consider, an exploit, as it seems to run contrary to the 'spirit' of the game's design. Just my opinion of course, as I'm not sure if this is considered just part of the game or not, but it is quite irritating.
Likewise, I dislike just hoards of pitbulls charging at you the moment you enter the game. The maze I used had just two, and yes while that did create a "Oh shit, I can't afford to make a wrong move" sort of chase-scene, a crowbar or some meat will easily solve it, and there aren't so many that any burglar would run out of supplies trying to deal with them. But when you're faced with literally more dogs than you could carry meat for, it's a bit frustrating... and for this reason, whenever I'm carrying guns/crowbars, I make a point of using them to kill the dogs in such designs. They are being abused by evil masters anyway, I consider it the only kind thing I can do; liberating them from such tyranny! Sure, I usually end up out of pocket, but I like to think I'm helping to contribute to their eventual downfall by taking a few of the dogs out of the wave for the next person who comes along.
On an unrelated note, I've discovered that while logged out, your avatar is out working and earns money based on how long you were away