The can and clay pigeons are extremely irritating if you give the dog enough space and you cannot beat them with your own projectiles. It forces you to go in and approach.
Watch out for the Dog's Fair and Bair. IIRC the duck doesn't have a hurtbox, meaning those aerials have disjointed hitboxes, and I'm not sure if it outranges Jr's wrecking ball... D: I think it will come down to timing and spacing (if the duck doesn't have more range than the wrecking balls)
If you launch the dog offstage, though, his Up B is totally harmless, so you can totally go in for the edgeguard, using side b and up b to make it back.
Unfortunately I myself need more experience dealing with this character as I don't see many Duck Hunt dogs on FG...