Poison Oak nightmare

This is my second spring getting poison oak but it just keeps spreading. There is a concentrated rash in one place and small 7-8 blister rashes in about 4-5 other places. The big rash just keeps growing? It started about 2 weeks ago.

Any ideas from those who have been here? What didn’t I wash down enough? I take my dog hiking a lot and I washed his harness but maybe I need to soak his leash? Any and all advice appreciated