Most dogs aren't a fan of being grabbed by the collar or harness quickly. Understandably, the quick movement can make them feel a little startled, resulting in them going in the opposite direction to you altogether.
Whilst this might be a perfectly normal reaction, there are some situations where you might need to grab them a little faster than you both might like. If your dog isn't comfortable with this, then it will make things trickier (and more dangerous if you can't stop them quickly enough in an emergency.
