@casportpony has more info on things like Tramadol - I don't know it.
But I do know that Advil is better than aspirin for pain.
From hennible's vet:
For ducks 6-8 lbs 25-40mg twice daily adult tablets cut up or children's liquid Advil 1.5ml twice daily, orally.
Amiga’s arithmetic – 8 pounds 40 mg is 5 mg per pound
6 pounds 25 mg, is just over 4 mg per pound
so, 4 to 5 mg per pound of duck
Storey's guide suggests clipping feathers away from wounds
keep away from flies (they lay eggs in wounds)
I would also consider getting oral antibiotic started - but see what others say - I would not want to wait for systemic infection to set in.
Definitely rinse the wounds daily - even saline solution can be really good, so can Vetericyn.
Some vitamins with electrolytes and probiotics to build the duck's system back up.
You have corrected the security problem, I hope, if that's what it was. I know things happen sometimes in spite of our efforts.