2d Animation and Colliders

Hi, I'm working on a 2d side scrolling platformer and I have come across a problem that I can't get my head around. I have an animated sprite for the player character complete with 2d Box collider for body and 2d circle collider for feet and in several of his attack animations he has a melee weapon in hand. How do I add a collider to that weapon to test for collision with enemy characters and/or destructible scenery? Will I have to rig my 2d sprite (using something like Puppet 2D) and instantiate a 2d weapon prefab complete with it's own collider into the characters hand or am I missing a really simple way to do this?

Thanks in advance for any help you can provide.