(Speaking generally, not to Chad in particular.)
You may know that you know what you're talking about, but how does that help others? You're just a name on the Internet, and Stack Exchange's goal for any site is for 90% of traffic to come from searches. Even if everybody here knows your credentials (which we won't, once we reach a healthy size), that doesn't mean the Joe Googler does.
Therefore answers need to show enough about why they're correct that an independent person can make an assessment. This can be through quoting sources or by sharing your credentials (probably among other things). "I've been a veterinarian for 20 years" and "I wrote my PhD thesis on this topic" and "the shelter where I volunteer does it this way and that's worked for thousands of cases" are all ways of backing up your answer.
So references, specifically, aren't required, but some form of backing up what you say is important. References are one way to do that.