The worst case we encountered of bad behaviour in a restaurant (not a bar!) was when we stayed at a well-reviewed and expensive hotel/restaurant on the south coast for a special anniversary. From one large party there was continuous calling out and wandering from table to table. Food, which had obviously been carefully prepared and presented, was being carried around and waiters impeded. Our long-anticipated fine dining experience, and that of other diners who had no doubt similarly looked forward to their evening out, was completely ruined. We had travelled hundreds of miles for this appalling behaviour. Yet there wasn't a child in the party! How adults think it's acceptable to wear beach wear in any restaurant is beyond me, but the behaviour and lack of consideration for other diners was astounding. These, of course, are the same parents who have no problem with their children wandering around in a restaurant. When we complained the waiter apologised and said had they known the party would be so bad-mannered they would have served them in a separate outside room as it was also bad publicity for the restaurant. But, obviously, they could not really do anything then as there were about 40 guests involved.
As for children, I think a bar is an inappropriate place for them, but they definitely should learn the enjoyment of eating out with their parents, as long as said parents put away their phones and talk to their children!
Dogs are a different matter. Having been penned into our table by 2 extremely large dogs lying on the floor, on a visit to a local cafe-bar lately, I was already quite annoyed when the waitress serving food patted them. We won't be going back! Surely basic hygiene, which seems to be going downhill in most restaurants lately, should prevent dogs from being taken into eating establishments. Don't get me started on how long we seem to spend clearing tables before we eat... Grumpy old woman alert! 