Hi everyone, im a newbie in the forums and I am very concerned about my dog! I have a 5 year old Havanese/Shih-Tzu and hes a great dog!!! Every few months or so he has some kind of "episode" where he appears to be very scared, his heart is racing and he cant get close enough to you and he is shakingnand panting! This is very unusual for him and im really worried! The last one was Friday night and they usually last for about an hour, but the one he had Friday night lasted for 3 hours!! What could it be and what should I do?! Thanks in advance!!