Use a trap to keep it in one location. Wait untill nightfall. Knock out your tame after setting it to nuetral and stand on it. The Troodon will hit it trying to attack you. To avoid getting knocked out, use a cheap Riot Shield. They bounce off.
At lvl 72 with flak armor on, a lvl 5 Troodon knocked me out with one attack at night. Last thing I saw was those glowing eyes before passing out. My Guess is that they attack vital organs. Luckily my Doedicarus was up for a game of baseball and launched that little devil out into the stands.