Well, we're back. I like the new Vet - she gave me several options for the treatment of probable "flea allergy dermatitis". I opted for the more hands-on route; will save steroids for "last-resort" needs. She said that dogs can develop allergies later; and that a flea allergy is a bad thing for a dog, since they're always a target for fleas; and fleas are everywhere.
I'm going to try Bravecto, the 3-month flea/tick killing chewable. She also said I can give Jimmy more Benadryl than I was; I also have a soothing oatmeal/aloe shampoo; and a topical cortisone spray. Ben will have to receive the Bravecto, too, lest he keep delivering bugs to Jimmy. I'm not keen on using pesticides inside or outside my dogs - but Jimmy is beyond miserable.
I guess I've been lucky that in all my years, I've never had a dog with recurring allergies. By the time the Bravecto wears off - we should be back in Michigan. It will be interesting to see if he reacts like this to Michigan fleas?
An aside: nobody in the Vet's office was familiar with Aussiepoos - and they were just goofy about my guys (who are lovable and super-friendly anyway). It also feels good to have a Vet connection down here. I also have a 24-hr emergency/specialty animal hospital literally across the street; but they don't handle "regular" Vet visits.