Yes, he absolutely needs to be wearing at the very least a warning vest. A dog that is a bite risk should also be wearing a BASKET style muzzle in public, one that allows the dog to open his mouth to freely pant and drink water. Something should have been done immediately after the first incident, but better late than never..
A harness like this should be worn whenever in public. You can still walk him on his collar though. (Sorry for the long links) https://www.amazon.com/Removable-reflective-Purchase-pathces-purchase/dp/B00BOWR0L0/ref=asc_df_B00BOWR0L0/?tag=hyprod-20&linkCode=df0&hvadid=241991316466&hvpos=1o4&hvnetw=g&hvrand=14292215627521083688&hvpone=&hvptwo=&am...
And or a basket muzzle. Preferably both as it’ll clearly be a deterrent, and if someone does approach him he at least won’t be able to do any harm- which could end up with you being sued/being forced to put him down. https://www.amazon.com/gp/aw/d/B0051H45GC/ref=mp_s_a_1_3?ie=UTF8&qid=1533692805&sr=8-3&keywords=basket+muzzle&dpPl=1&dpID=51Mvx6m1ufL&ref=plSrch
This is part of a photo set, which got turned into a kid's book. My son loved this book when he was younger.
This meme accurately applies to my dog. She also loves these dog kabobs.
You posted a link to where you found the picture in the comments on the same picture in r/Floof. The source clearly says it’s an Eurasier.
https://pixabay.com/photos/dog-pup-puppy-dog-eurasier-5216396/
I actually ordered one last night because there was an Amazon deal on them! It was this one, but I’ve seen other similar ones.