After taking Building the 3D Character, SOFA 583.01, at Rochester Institute of Technology I followed up with an independent study in rigging. The assignment for the independent study was to build a working quadruped rig.
After working with an FK/IK spine with the biped I wanted to explore another technique that could be used for the spine. So, for the fox rig I used a ribbon for the spine as well as the tail.
For an animal such as a fox the ribbon spine seems to create good results in the curvatures of the spine and tail without an excessive amount of controls. When I had animators play with this rig they too agreed that the ribbon spine flowed well and was easy to use. For the future, however, I think adding at least one more control in the center of the ribbon spine will bring better results.