Fulgour, that is plain unhysterical
I do take it that there are no depicted dogs on the Marseille (or other) cards of Le Pendu... however,
if the depiction - or worse, the actual act, occured with even a minimum amount of regularity (which posted images at least
suggests), then it would have been a living presence in the minds of the many European Jewish communities, and especially those who may have lead a Jewish life in hiding (the 'Crypto-Jews').
In a similar manner that the Pances/Papess, if depicting the Annunciation, does not need to depict the Angelic presence towards which she faces, nor does the Hanged Man need to depict the whole scene.
Also, as pointed out, the images so far seen are
either of single leg hangings, or of both legs with 'companion' dog.
Personally, I suspect the dogs are as or more likely to have been strays used for the occasion than dogs used for protection or work by the community.
In terms of the iconography settled on, it also makes more sense, from a woodcarver's perceptive as well as from more symbolic considerations, to have the single leg without the redundant (and brutally repugnant) dog shown.