Emergency- using Cephalexin for duckling with respiratory infection/pneumonia

[WhiteTreeOfGondor]

I ordered Baytril but it hasn't arrived yet and I need something fast. Has anyone had any experience with using Cephalexin for this issue? According to what I've read it is usually given for bumblefoot but can be used for respiratory issues as well. The duckling is only 3.88 oz so dosing based on 50 mg/kg, I cane up with 5.5 mg of the Cephalexin. My capsules are 500 mg.

 

[WhiteTreeOfGondor]

If there's any way I could put some in it's water, it does drink still. I'm just not sure how much to put in. It's using a little dish with about 1/2 cup of water right now.