@Emily has shared a great suggestion for creating a "dog digging patch". See this post - https://www.workshop.com.au/t5/Gardening/Dog-Digging-Patch/m-p/9444
@Jason, thanks for digging his thread up, I hadn't seen it.
Tania, my gorgeous wife of nearly 43 years, discvovered a remedy, where you put a doggy poop where they've dug. It's worked amazingly well, but I can't walk anywhere outside without a dig deterrant lodging on my sole.
I mentioned that our yard is now full of sh*t, to which she replied, "that's true, but after all, it is your signature garden".