Mercedez,
This is actually not true. Not all dogs are going to react aggressively or at all if they have been desensitized to certain stimuli. I am not against muzzling aggressive dogs that are not safe, but my point is that a dog that is not properly trained and/or dogs not have a stable temperament should not be on a bus at all. However, a stable, sound and well trained service dog is desensitized to this before being put in the situation. I totally understand that it's important to keep everyone safe, but again if the dog is NOT safe around humans, he is not cut out for service work.
Vicki
I do not think service dogs, who are trained properly, should have to be muzzled.