Originally Posted by
MSPeconomist
You can test the behavior of the ESA. Behavior in public is part of the way genuine service dogs are trained. They're supposed to cope with crowds, not bark/snarl/lunge for no reason related to their special task(s), walk nicely and stay near the owner unless commanded otherwise, etc. A true service dog wouldn't snarl at another animal it sees or lick a stranger, and it would stay it its own space.
There's a difference between a service dog and an ESA. Also, any dog can have times where their behavior is off. An ESA could growl or snarl at another animal it sees, if it feels the other animal is a threat (like if the other dog is close to attacking the ESA's human). Growling and snarling is one way dogs communicate. If they feel another dog or even a person is a threat, they may growl to communicate that. Empress Cobaka, who isn't an ESA or a service dog, but who loves all people, growled once, when she felt another person was a threat towards me. As a side note, I would much rather have a dog growl than not, because a growl tells me a dog is unhappy before they bite. A dog that has been trained not to growl may simply attack without audible warning.