This struck me today while watching Enterprise. How exactly do you house train a dog living on a starship? It's not like you can let it outside to do its business?! If Cpt. Archer left Porthos shut up in his quarters all day while he was on the bridge, it must have stunk in there by the time he got back at the end of his shift. Maybe his quarters were equipped with their own minitransporter system to beam any dog crap directly into space once Porthos has deposited it. Any other ideas?!