Will 2 quality articles of 500+ words be enough to use adsense? I've already got a warning before for using adsense on a low value page and don't want it to happen again. My site is dogallergysymptoms.org if that helps.

Sure dude. That's fine. Now take action and don't look back! BANK HARD.

Hey mate.
Yes, that's fine. But if you want to grab the most out of it, I advise adding some content on a weekly basis, or every 15 days.
That way adsense will give you more credit, and put the most pricey CPC ion your site.