Iv never let mine of their leashes and the main reason is that yorkies are VERY fast.They can also get distracted easily and I just cant imagine what Id do if Lady or Jess suddenly started to run (which I beleive they would)..I dont think Id be able to catch up with them and they could run into a road,get lost or stollen etc.
Iv always wanted to take them for a run on the beach without their leashes and I envy those who can actually do this,but In would rather be safe than sorry because it only takes one second for something bad to happen and at the speed my two run,I wouldent be able to prevent an accident
Instead I use 10m (32ft) retractable leashes and they work fine for me.They can run a long way ahead and if anything happens (like a big loose dog etc) I can quickly wheel them in to safety.