That is such an excellent question because I’ve been wanting to build a ramp for my bunnies since I’m building a larger cage, so I’ve been wondering it myself. For a makeshift ramp, I’ve been using a piece of plexi-glass, that has pieces of ply wood drilled into it (so that they can actually get up it without sliding down). The ends of the plexi-glass are filed down so that it cannot cut the buns, and so far, they haven’t attempted to chew it (I watch them like a hawk if they are using it). So, I just realize that I was of no help to you, but I’m sure that someone will come along and answer your question.

Pine and Cedar are also safe woods (they are used for small critter bedding and although not idea for bedding they are not poisonous)

I would absolutely steer clear of cherry wood and any wood that comes from trees that have ‘pitted fruits” (fruits with pits) as they contain arsenic until fully dried -and you don’t want to take chances.

Also, rabbit.org has an excellent ‘poisonous plants’ list; It’s not comprehensive-that is, just because something isn’t on there, it doesn’t mean it’s OK but you could use it to determine what not to use.

I would recommend PINE though; It’s safe, and cheap! Non-treated of course!

Check this link at the House Rabbit Society about Pine and cedar shavings. Apparently high levels of liver enzymes and anasteshia deaths were linked to pine and cedar bed shavings.

http://www.rabbit.org/journal/1/liver-disease.html

Aspen is the most recommended wood for pets/rabbits. Apple is also good but buns find it tastey so expect a lot of gnawing on the ramp. I do believe though that untreated pine will work. Fresh, living pinewood is dangerous because the sap in the tree can be toxic however during the kiln drying process of pine, these levels of toxicity are reduced almost to nothing. In other words, yer bun would need to eat a 1×4 in a week in order to take in enough toxins to cause damage.

Did you know that most bunnies don’t need ramps. They can easily jump from level to level. Our 2 are 6-7 lbs. & have no trouble with the 14in. shelves in their condo. If your bunny can’t jump that high try a box as a mid-level step. I think ramps just take up needed cage space. I would only use them for old or disabled rabbits.

Pine is ok, most good bunny safe toys are made of maple so you know it’s good.

I’ve used pine for ramps, but have steps that I made for them instead – they are BIG chickens jumping up to the next level without one even though they are quite large enough to accomplish it. The “step” I made out of pine and covered in carpet are about 5″ tall. The ramps I have made are 1/2 the width of a NIC panel and 28″ long. I put 3 cup hooks in the end to hook over the floor and hold it at and angle and secure with a zip-tie. I covered mine with carpet that I affixed with carpet tape. My two leave the ramps alone as far as chewing goes, however you can buy some “L” shaeped aluminum in the metal “welding” section at Depot that you can cut with a hack saw and drill holes in to affix to the sides over the carpet to keep your rabbit from chewing it.