I also use doTerra, though it is worth noting that their Certified Pure Theraputic Grade has a TM after it, which means that they are self regulating. There is no industry standard for oils.
After having worked with several different brands, I prefer doTerra, mostly because that's what my animals prefer. They tell the truth in what feels best to them, and they kept going back to doTerra hands down. So that's what I use. I've been using essential oils with my animals and myself on a daily basis now for 6 years, and have taken several classes and shadowed people that use them in their holistic body work practice. Feel free to pm with questions.