My dog ran away, what can I do?

The guy who fixes our garden let my little maltese shih tzu run out the garage door, hes been missing for 7 hours now and we only found out 2 hours ago, weve rung vets, pounds and are putting out flyers tomorrow, hes micro chipped and has a collar! is there anything else I can do, he doesnt usually run away from home he usually sits out the front when he gets out the front door