Wheelchair for small dog/cat

Remixed this from marianagarciacorra excellent Front dog wheelchair (simple) https://www.thingiverse.com/thing:1629064 for a disabled chihuahua someone asked me if there was anything I could do for him.
Have made the legs wider and lower with a 8mm hole to accommodate larger easy run wheels I got from an old inline skate some one was throwing out.
Added a support wheel at the back and used a piece of Evazote foam to act as a suspension spring which seems to work fine using a small 2" solid wh