golden retreiver allergies? drewling?

[Debrahdci]

I am new here so please bare with me....my golden retriever is sick again. Every August she starts to drewl (sp) and her throat swells. I have her on benadryl and antibiotics but she is still stuggling. The vets can't figure it out it seems. Anyone have any ideas or been through the same? Any help would be appreciated as I am getting nervous now. Thanks, deb