Collecting squirrels

Have I mentioned before that I have a fascination with portraits with squirrels in them?  I've seen a few mentions that squirrels were popular pets in the 16th century and I've started digging for more information on that.  In the meantime, I just started a folder and have been shoving every squirrel portrait I find into it.  I think I'm up to about 8 so far.

I just found this one this morning.  Called alternately Double Portrait or Family Portrait, it is Lorenzo Lotto.  Dated 1523-24, it is currently in Russia in the Hermitage Museum. It is a little hard to see, but he is pointing to a squirrel at the center of the portrait. 
While squirrels were usually in portraits as either pets or as symbols of obedience and personal restraint, The Continum Encyclopedia of Animal Symbolism in Art by Hope Werness, has this one as symbolizing infidelity.  As the dog is for faithfulness and the squirrel is the dark center of the portrait where the couple is basically miles apart, it is certainly an intriguing painting.