Neva's itching has improved significantly. Benadryl tablets have been effective for the last week. The cause seems to be a potential flea or mite bite. Thankfully not an allergy which would have been almost impossible to determine and control.
We stopped oral medication and are now treating her topically. She gets a bath every three days with a medicated shampoo. The most recent being this evening. Did I mention that the directions were to lather the puppy with the shampoo and wait ten minutes before rinsing. It is quite the chore to occupy a soaking wet, soapy puppy for ten minutes, indoors.