When you upgrade tp 0.11.0 build 8 from 0.10.5 with an existing world, an existing dogs that you have now have white collars.

At first I thought they didn't have collars, but I was able to succesfully dye one blue.

There is no longer the option to get them to sit or stand and, if you hit one, they will all attack you. If they're already sitting down, they will still attack, but only when you go closer to them.

Have attached a screenshot to demonstrate how the collars look.