I have seen dogs who lived exclusively in wire mesh/expanded metal floors have jacked up feet. Especially if the holes are large enough for parts of the foot to go down in them regularly. I like to use wood decking boards myself. They are spaced about 3/4" to 1" apart for easy cleaning yet the dogs foot can't get between them. I have seen people who use brood type pens for permanent kennels/housing. It is an easier clean and it does not expose the dog to things on the ground. I would prefer the dog have the ability to move about on a chain spot but to each his own. EWO