something attacked...2 injured chickens return after 3 days....

a few evenings ago the geese were making an awful racket in the field, but after a search round we couldnt see anything so went back inside. the next morning in the light we saw a few 'piles' of feathers here and there...and three missing chickens. 2 red laying hens and my non-silkied silkie.
i didnt even bother searching further as i presumed they'd been eaten due to all the feathers left behind.

anyhow this morning 2 chickens have re-appeared in the field....one red hen and the nonsilkie silkie. the red hen will not put any weight on her left leg...but i see no visable injuries? i cant feel any breaks nor see any bruising but she will not use that leg.

the non silkied silkie oon first glance seemed unharmed so i watched her for a while and noticed she kept her distance a bit from everyone so i decided to catch her too. (and that was a lot of work...she's mighty quick and can fly!)
on closer inspection she has some big wounds on either side of her body (on the underneath/abdomen and chest areas) and a large wound across her thigh, theres lots of large puncture wounds, non are bleeding anymore but she has lots of dried sticky gooey blood around them and they are weeping. there is also an odour..not like dead decaying smell but 'old blood' smell.

ive brought her inside also and caged her with food and water..she seemed intrested enough in both and is loudly protesting at her being locked up. but how do i go about cleaning these 'old' wounds? they must be 3 days old now? if it was a fresh wound id clean her up and let her heal, but as these are a few days old and 'gooey/oozing' i'm looking for a bit more advice.....should i put her on antibiotics? (i have denagard to hand) should i pluck around the wounds? (shes very fluffy down there and the fluff is sticking in the holes)

what should i do with the red hen? keep her as still as possible and let her 'rest'?

 

thats what worrys me most is infection so do i bathe her everyday or just dab around the wound with warm water? should i put any kind of cream on the wound or gauze or leave them open to air?