I Am An Experienced Horse Person, Run A Horse Rescue.

I am an experienced horse person, run a horse rescue. I have Dexamethazone on hand...My dog was stung by a bee today and her jowls are swollen. Its not bothering her, she doesnt appear to be in pain. She did this once before and $100 vert visit, they administered Dex and an anthistamine. I also have Hydroxyzine antihistamine powder. Wondering what you recommnd I give her in the way of dosage, I would just add it to her feed and not inject her,,
Sorry I thought you were a veterinarian...never mind.