Foster horse coughing. Allergies?

[dacasodivine]

I have noticed before that when a front comes through, she coughs a little. Sunday evening a front came through and she was coughing pretty bad yesterday (Monday) evening. I shouldn't say bad as much as regularly. She's eating and drinking and looks bright.

I checked on her later and no cough but she is still breathing a little hard. If I get down right by her nose, I can hear her breathing. Not rattling or really weezing.

This morning (Tuesday) I checked before and after feeding her. I can't hear her breathing unless my ear right at her nostril. It kind of reminds me of someone that has asthma and has maybe a mild attack? That's what came to mind yesterday.

Is there something I can give her for days like this?

Thanks all.