per bartleby, taxes appear to be linked to cats, dogs, and sheep:

taxonomy: Division into ... categories.
and reciprocally:
category: from Greek katgori, = accusation, charge. a charge, reminiscent of a tax

more animal found by bartlebying "category" back further:
category: kat-, kata-, = down, against; see cata– + agoreuein:
A) cata–: directs us to: kat- ... Suffixed form ... from Latin catulus, young puppy, young of animals (“dropped”).
B) agoreuein: bartleby directs us to ger- DEFINITION: To gather.
-1) extended form from Old English crammian, to stuff, cram reminiscent of "taxidermy"
-2) Reduplicated form ... from Latin grex herd, flock enter the sheep!