I think orangeskittles makes an excellent point. Although I understand social anxiety and understand how overwhelming it is for people to go out without having someone or something to accompany them, it does beg the question that if a dog is brought to a theatre then what are the chances of others being affected? Unfortunately, allergies to dog hair exist, as do allergies for cat dander and pollen. While it may relax the person who brought the dog, it may cause an issue for other patrons. (Personally, I find going to therapy for anxiety helps a lot, but that's just me!)
As for chewing gum, I've never had the problem of dealing with an unruly gum chewer. Rather, I have been seated next to people who have eaten their candy/chips loudly, texted on their phones the whole performance through, and those who thought it was an excellent idea to answer their phone in the middle of a very important scene.
"I am and always will be the optimist. The hoper of far-flung hopes and dreamer of improbable dreams." - Doctor Who
"Yes, the brutalities of progress are called revolutions. When they are over, men recognize that the human race has been harshly treated but it has moved forward." - Les Miserables