He's old enough to xray for prelims if that will help your peace of mind, HD can be diagnosed pretty young especially if it is moderate to severe.
It's up to you, get the xrays done now and then redone at 2 so they can get an official rating or wait until he's 2
Jasmine - Female Miniature Poodle - born Aug 15, 2010
Loker Delgado Von Stalworth - Male GSD - born Jan 26, 2012
Koda & Zazu - 5 year old male cats
Alex - Male Cocker Spaniel (rescue) - RIP Cuddlebug 2007-2010