duck not eating since fox attack & wound on back

clean her wound with cooled boiled water then pat dry. Apply some wound powder to the wound - this is an antiseptic and will help keep the wound dry. Do this daily.
As for food try your duck on a mash - made with boiled water and pellets then cooled off - make it quite sloppy as her throat could be sore from quaking when the attack happened or if the fox could have tried to grab the neck it could be sore from that. You can buy avipro plus - which is a powder that can be mixed in water and this will help, good luck x

Thanks for the advice . I called wildlife recuse centers they all had different advise though ! I tried all of them i bought so powder glucose and added some to her water i found a large box she couldn't get out of and added straw to it i also bought some Hypocare - Infection Control Spray for Animals - 250ml
last week as after we got her in a settled a few days later we found a wound on the back of her neck and just above one wing after using for one week the wounds have heald i put her in my shower lukewarm which she just loved  never seen her so clean !! Today she was outside her mates run she started eating !! But i want her to put some weight on before she goes back so hopefully by this weekend she will be back with her mate and chickens caked in mud !!