I have a website (www.equispot.com) that has been indexed for almost 2 years in Google. I managed to get myself on the first page (average position 6-8) on Google for my target keyword of "horses for sale" and held there pretty solidly for months.

Suddenly, with no changes to the site, traffic from Google dropped like a rock in early May. I slowly fell in position until now I'm sitting at the bottom of page 4.

I have never hired an SEO firm, have not used any "black hat" techniques that Google would have penalized me for in their May update, etc. I'm not familiar enough with SEO to know how to look at link profiles, etc. to tell if there's something wrong.

I've run my site through a DNS checker and it came back with no errors. Google Webmaster Tools shows no messages or notices of any kind, just a drop in traffic. GWT also shows only 2 server errors and 1 404.

Is there anyone who can tell me by quickly checking my domain if there's an obvious reason that my traffic would have fallen so far, something that I can fix?