I met some hikers in Old Station on the PCT who had just been kicked out of Lassen Volcanic Natl Park for bringing their dog through it.
They and their dog were unceremoniously put in a vehicle, driven to the nearest gate, and dropped off at the road, far from the trail. I don’t know if they got a ticket; they didn’t say and I didn’t ask. They had just finished a LONG roadwalk.
Legalities aside, do your dog a favor and don’t try it. Use the search function on any PCT forum and you’ll get loads of threads all on the same subject. It’s an annual feeding frenzy topic, just like guns.
wandering bob