Riccilove-I used to think like you did. You don't really NEED to have the extra money aside...
Until my horse had to have an emergency surgery. The vet did take payments plans but there were strict conditions.
-The last two payments on 25% had to be paid every two weeks. So you had a month and a half.
My bill was $3000ish, so they needed $1500, before she could come home and then $750 two weeks later, and then the other $750 two weeks after that.
Thank goodness I had the money to pay for it, otherwise I would have been up **** creek without a paddle.
I'm not saying you are a bad horse owner, but it might be worth trying to put at least $2k aside for a just in case day. If you can't, that's okay too as long as you are caring for you horse and have a back up plan if something does come up!