FINCHforum

This morning I noticed blood spots, quite large, toony sized, about 3 in all on the bottom of the cage, one male gouldian on the floor uninjured, other male on perch in corner, his mate hiding in plastic plant in back corner and younger female sitting on perch.

On looking further younger female has ruffled chest and blood stain.

Should I separate her and maybe her mate?

I obviously will pull her out to examine the injury, I put fresh seed in and they are all eating fine, how should I treat this injury, should I give her antibiotics?

Never had issues with fighting before, they have been together since February.

You need to do an examine before any advice about how to treat. Wound could be minor scrapes in which case just a antibiotic ointment may be enough or it could be deeper if it's deep you need to consult a vet and the bird will need antibiotics. Sounds like it's probably minor but won't really know till you check. If there is any significant wound I would definitely separate the injured bird out. Birds fight...over mates/nests or any of other reasons. Watch them close if it continues you may need to separate the pairs. I would not give antibiotics for minor issue only if it's deeper and ideally only on advice of a vet, as antibiotics cause the same issues in animals as humans. If you have to do antibiotics I'd add probiotics at least an hour after each antibiotic dose.