I do not yet own Pets, so if the answers to these questions are otherwise obvious then please forgive me.
Can horses be taken abroad, or is my aesthetic for romanticism getting in the way of my better judgement?
If they can join in on a sim's travels, what are the practical aspects? I can imagine they will not and shouldn't enter tombs (otherwise I shall name them Laura Hayloft), and there may be difficulties fulfilling their needs (but surely foreign worlds could easily be edited to accommodate this?), but their haste and companionship would be a plus.
If not, how are pets cared for at home while a sim is away, is there a petsitter sort of arrangement available?
What of dogs and cats; I am sure their hunting skills would prove invaluable and that they could atleast partially navigate tombs.