what type of collar are you using on your walks?
I agree with teaching him to ignore other dogs while your walking, and I would keep him ON leash/long line, as you say to not bug/disrupt other dogs.
Danger Danger vom Kleinen Hain aka Masi
"Angel" Jakoda's Bewitchen Sami CD OA OAJ OAC NGC OJC RS-O GS-N JS-O TT HIC CGC
"Angel" Steinwald's Four x Four CGC HIC TT
"Angel" Harmonyhill's Hy Jynx NA NAJ NAC NJC RS-N JS-N HIC
"Angel" Jakoda's Jagged Edge