Not sure if this will help but there is a video here showing what the war horse actually looks like. Like myself a few people on youtube are asking what happens if it dies. Surely they wont charge you extra for something that will be gone in no time.
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EDIT :
Ah , I may have found you're answer mate. After reading this it would seem there should be a ticket in your inventory which gets you to the war horse. I haven't even played this game yet so I'm not sure if this info is correct or not.
https://answers.yahoo.com/question/index?qid=20100519021914AAiarYB
That person also mentions they have killed they're horse a few times and you can keep spawning it back using the same ticket but they're also asking if the ticket ever runs out , personally I doubt it will.