The weapons are suited to animal bodies. 

A gun would have a different firing mechanism than an earthly gun.
 A bow and arrow would be slightly different- maybe pulling the bowstring with your tail (or if your animals has the ability to stand on its hind legs, maybe one of it's free arms).
Maces and such could be swung with the mouth, tail, ect.

How the weapons look and are activated (gun, gunblade, bow and arrow, ect) is up to you.