Goats are voracious consumers of poison oak and ivy. Nurseries or the agricultural extension office can point you in the direction of goats for hire. Use a glyphosphate-based herbicide to kill the plants. Glyphosphate is a nonselective herbicide and will kill any plant it comes in contact with. Keep it away from your landscape plants.
Herbicide works best on poison oak that has already formed berries.
Wear long sleeves and gloves when handling poison plants. Wash all clothing and tools immediately after you finish working. Shower to remove all the toxic resin from your skin. The toxic resins will be carried in the smoke and may damage your lungs. Even the bare twigs and branches of these plants are toxic during the dormant season.