I have a 13 month old Italian Greyhound who is very good at going outside for toileting, but I may be moving to a small apartment and I am considering box training him for convenience and his comfort during possible longer hours and cold weather. When he was a puppy he used puppy pads, but his best buddy always tore them up (and he could have been involved too, but I am not sure). I am aware that if my dog eats litter he can become very ill – and I would like to avoid that. Are there any other suggested materials (I have thought of wood shavings or cedar chips, but have to reference of whether it would work and possible ill effects or such) besides paper, puppy pads, and litter that I could use? Also, if he were to live with cats while being box trained, how would you suggest I teach him the difference between the boxes? Is it possible to put them in the same room wihtout any conflict?