My 1 yr old was prescribed prednisone 3 days for croup. after 1.5 days she is better can i stop giving her prednisone or do i have finish the dose?

Yes: If she is significantly better you can stop.However, sometimes they need the extra day or so or the swelling can return. In the overall treatment, 3 days is unlikely to cause side effects. If she is cranky and hyper as a side effect, stopping may be better if she is passed the barking.

Finish if tolerating: Croup is usually short lived, hence the shorter course already prescribed. It is possible that the symptoms could return once the prednisone wears off. I would recommend finishing the prescribed course. That being said, croup is often treated with a one time dose of decadron (dexamethasone) in the emergency department... but this is a longer acting steroid.