We have CP Kitten pens, nursing mother pen and 5 large dog crates and the dog crates were cheaper than the other 2 by a long way and are great for kittens - also if moving cats the dog crate gives room for litter tray dependant on the distance also dog pens have secure bottoms and 2 doors with space for padlocks and were used to move our mob - the crates were a success but they broke the window to go out!!!!