Wire cages aren't all the bad for wire cages. This is a copy of my usual response to housing rabbits on wire flooring. (my cages were recommended to me by a vet, yes a vet, and they have never had sore hocks! However my grandmothers house rabbit has. It really does depend on your rabbit.
I had concerns at first too, keep in mind I started with a house rabbit of my own and eventually worked my way up to the small rabbitry I have now. Also keep in mind we may live in different countries, the USA allows wire cages.
So the first concerns usually with wire cages are that they hurt the feet. The wire can but if you consider several things the cage will not cut into their feet.
The gauge, size of the rabbit, resting pad or litter box, size of wire, thickness of fur on the rabbits hock, support of the wire cage, rustiness, ect.
The gauge for a wire cage; you do not want under a 16 gauge, under that amount will create to much friction and it will not be safe for the rabbits foot if there is just a wire bottom and no resting pad or litter box. !4 gauge is recommended and 12 gauge is great! My rabbits are on a 14 gauge, meaning the wire is thicker and not as thin.
The size of a rabbit; my four pound and less rabbits aren't going to be putting much pressure on the wire, the floor will not affect them as much as it would with a 15+ pound Flemish Giant. So the size of my rabbits on the wire will not affect them that much. It would be like going across a forest flooring.
This brings us to the size of the wire. Usually the flooring is 1"x.5" for the flooring this usually is ok for most breeds, however once you get to the bigger breeds once again referring to
Flemish giants it is better to have a .5" x .5" flooring. This is because the smaller spaces in the flooring allows more support for the hock and doesn't allow as much friction to rub against the fur of the hock. (this was in one of my books I have bought, written by a vet, so I don't know if the size of the wire affects the flemish)
So now you may be wondering why i keep referring to the amount of furring on the hock. The thickness on the hock of the rabbit is different for each breed, some rabbit breeds are prone to sore hocks, like the rex breeds. The rex breeds have very thin furring on their hock and get sore hocks very easily even on solid bottom floorings with cushioning. If you watched my cage setup video all the way through and commented after you would have saw me explaining this. My hollands have VERY thick furring on their feet, it is very hard for a holland lop to get sore hocks in a wire caging because of how thick the furring is on their hocks.
Resting pads/litter box/ect. ; I dont know if you were looking in the cages or if you commented as soon as you saw the cage(i guessing you just commented) But my cages have resting pads and litter-boxes. The resting pad is recommended for all wire cages. This basically is something the rabbit can go on to rest its feet from the wire if the the wire begins bothering the feet of the rabbit. I also use litter boxes mine have a natural material in them which mimics the flooring they would find outside. This is also a good place they can rest at if the wire bothers their feet.You can also use other things like the back of a ceramic tile. This is great! Not only does it file the nails but it also allows the rabbit to rest its feet.
Rustiness; this is a pretty obvious one but you dont want the flooring to be rusty as this will hurt the rabbits foot. Fortunately breeders replace cages once they become rusty and believe me it takes years for the cages to get rusty!
Support of cage; this is a big one an unsupported bottom of the cage can cause the rabbits foot to bow unnaturally this can lead to sore hocks. Thats why its good to adjust the cage of
your rabbit to the size. Thats also how I know my cages work great for my 4 pounds and less rabbits!
Outside verse caged; I don't know if I have mentioned before but I work at a rescue and help rescue rabbits just let go. Some are rex rabbit that have been running around for 6 months, when we bring those rabbits in they have sore hocks. But how? they are outside running on the place we humans try so hard to mimic. Its the thin furring on their hocks which causes them to get this, even outside in their natural environment.
The flooring also needs traction if you rabbit is slipping when walking your putting unnatural pressure points on the joint which can cause sore hocks. So letting your rabbit run around on your kitchen floor... not so great of an idea. They should always run around on carpet or the grass.
As to putting towels in the cage, it would defeat the whole purpose of having the wire cages, wire cages help keep the rabbit clean. Once you get more than 2 rabbits the level of the commitment also increases. You wouldn't know this unless you bred rabbits yourself, which you obviously don't.
Keep in mind its not just wire cages that can cause sore hocks, wood, tile, and linoleum flooring's can also cause sore hocks. Rabbits needs a spot in their cage that mimics the natural earth, that doesn't mean their whole cage has to be soft like outside, you need to make sure you have a spot that your rabbit can rest. That is the most important thing.
OTHERS THINGS THAT CAN CAUSE SORE HOCKS.
Information received from vet related website.
Arthritis or other skeletal problems - Pain from arthritis in the pelvis or spine--or skeletal pain for any other reason--can cause a rabbit to posture in an unnatural way, resulting in pressure on delicate points of the feet. End result can be sore hocks.
Obesity - A rabbit with too much weight on her body will often not be able to stand correctly, and may put unnatural pressure on points of her feet that are not meant to support much weight. This can cause sores. >> This one is related to house rabbit in particular as many owners overfeed their rabbits, because they like to treat them like a person.
This next paragraph is from the website and a good source of information(stating wire cages are not bad for your rabbits feet and will not hurt them)
Improper flooring - Rabbits need soft, preferably malleable flooring that will mimic the natural texture of the earth as much as possible. Wire flooring that doesn't have sufficient SUPPORT underneath is not appropriate, as it can cause the foot to bow unnaturally. (Wire flooring with proper support is perfectly fine as long as you have a clean litterbox and soft bedding on top of it.) Wood, tile, or linoleum flooring can also be problematic, as it doesn't allow the foot to bend the way it does when it's pushing off against earth or grass. Cages with slick plastic bottoms are especially bad for a bunny's feet and joints. Lack of traction can cause painful problems in the pelvic and pectoral joints, leading to arthritis, and even "splayleg."
Good websites to read-
http://www.bio.miami.edu/hare/sorehocks.html
This is an especially good link to read-
http://shinysatins.weebly.com/wire-floors.html
Sorry for this being so long,its just that people always say that wire cages are bad for the rabbits foot and they usually say that they always cause sore hocks but with the proper things in the cage the rabbit should be perfectly fine! Usually people in the USA breeding will use the wire cages. I recommend if you have a house rabbit to give your rabbit an NIC condo because you will only have one to two rabbits to clean up after. Also please don't hate, this is just my opinion and my input. I understand why people hate on the wire cages, but they aren't that bad!
MY info from multiple vets, specialist , classes, educational websites, books, ect.
