I heard around (can't remember where) that caches will eventually change monthly... I think? That's why when you look at UC selling guides and safe transferring it will tell you to house the pet on a side for a little bit before advertising it or putting it on your main. Also I believe cache lists are based upon traffic so if you let it sit long enough the cache clears...
I don't recommend that caching link at all for pets.
You get a 'double flash image'; and I know some legit PC'ers flag this as a sign of illegitmacy.
@(you need an account to see links)
At this point just give the pet a lookup, update it slowly everyday and refresh the pet's lookup like an hour a day.
and yes, it will re-write the old cache. c: Cache updates constantly!