I'll throw some ideas out there.....

Post the ingredient list of her food and the ingredient list of the Furminator treats. Then we could try to see if there is a "likely" culprit. She's also in the age range where we see the development of food allergies (33% of dogs developing food allergies were less than 1 year old and 51% were 1-3 years according to one study).

Even just one (long gone!) flea could cause long-term itching...if she has flea allergies. I know they are pretty rate in Utah. It's a possibility.

There are definitely other parasites that are more likely to become problematic for a younger dog, so those are also possibilities. Again not super likely in Utah.

Is there any localization to the itching? I know you mentioned when you're petting her you stimulate it, but what about otherwise?

In terms of environmental/seasonal allergies (atopy) - you would probably see itching manifesting as face rubbing and foot licking. Not always, but usually. Are you seeing this?

If her skin is not reddened at all, then it's probably fairly minor. If it's getting severe or chronic you will start to see skin changes in color, texture, etc. It's quite possibly nothing significant at all. Otherwise the top three causes of itchiness are probably food allergies, parasitism or atopy.

I hope Keva is itch-free soon! Maybe she is just adjusting to the heat and her coat is bugging her since it's still fairly thick (heat rash kind of thing?).