According to some guidelines I read crib mattresses should not be used on subsequent children as it is thought to increase the risk of SIDS. Now scientists don't yet know what cause SIDS they are just guessing and if their recommendations result in less deaths they learn something, either way I'm not taking the risk!
I was given a crib, mattress, and some sheets from a friend of my aunts. We knew right away we weren't using the crib mattress for the baby. I have been looking for a bed for my bigger dog Shadow for a while now. He no longer needs his crate, and I want an area where I can tell him to "go to bed" and it be clear where that is. I also wanted somewhere comfy for him (although he doesn't seem to care where he sleeps!). With the crib mattress laying in the hallway it seemed perfect.
I grabbed it, one of the sheets we weren't planning on using for the baby (a plain white one) and instant dog bed! He hasn't really used it yet, he is still unsure of it but I plan on teaching him it is his bed and making him comfortable with it!
I'm not the only one who has had this idea. I pulled the two pictures below from a general internet search. gluesticksblog actually teaches people how to make a mattress cover, I'm just going to recommend you buy one (unless you know how to sew). Crib Sheets can be found CHEAP second hand, you can change it out to cheat a unique look, and it is easily washed!
Since I received both the crib mattress and the sheets free his dog bed cost me nothing whereas for his size dog beds can easily cost $80 or more! If you didn't have either on hand crib mattresses can be had cheap used as can crib sheets... my absolute favorite crib sheets though are at potterybarn and are SURPRISINGLY not all that expensive. I don't shop there due to the prices but I found some great clearance sheets, and great prices for organic sheets!