[debono]

The use of the word MAY instead of SHALL means the restaurant does not necessarily have to allow the dog.

He MAY allow the dog and not be fined for breaking any laws.

So the restaurant staff is right.

The person with the guard dog has no right to demand a place in the restaurant when she is with the dog.

I remember a friend who has a dog.
He always put the dog outside the restaurant tying the dog to a lamppost.

A normal dog is not a guide dog, and they are not properly trained to behave in an urban environment.  A guide dog on the other hand is trained to behave and guide the visually  impaired to a eating place, and behave properly..............