You have your windas open? So, I reckon you'll have to act fairly quickly- unless
( I'd have to do some review to make sure I had not forgotten, and to gather proper chemicals- probably a tanning solution)
So to buy some time I would wash the thing in dawn detergent. Wring it out then salt it heavily, roll it up, bag- then pop in the freezer. How you tan it, imo, depends on what you want to do with it. Roll it up into a rawhide fetch toy for Max or make a cap? I could go look up the name of the tanning solution, it's not super expensive and could tan a good number of trespassers