[Help] Duck got a cold

[dido123]

I have one duck, who has a history of respiratory issues. These past few days it's been very cold outside (below 0° celsius/32° farhenheit). Two days ago it also rained and my duck started to sneeze and pant slightly, so I brought her in the house for a while where she warmed up and kept ruffling her feathers. After that I let her be on my porch and she was fine and she didn't sneeze after that. Today I noticed her eyelids are slightly red, which they weren't this morning. Her eyes are not runny and the feathers around her eyes are dry.
Should I be concerned? The harder breathing is unfortunately a thing that periodically happens to her and it's sometimes much worse than now. However the slightly red eyes are something I've never seen before.
I am already giving her vitamins. Pictures of duck attached.

 

[Goosebaby]

She might have something brewing but it’s hard to say. You could try vetrx on her breast and apple cider vinegar in her water to clear her sinuses. If she worsens I would suggest an antibiotic but for now symptomatic treatment and keeping an eye on it would be best.