A frequent issue in dog Rescue is whether this particular shelter dog is really the breed the rescuer thinks it is. With those hairy breeds that normally require grooming to shape their appearance, the long neglected shelter dog can look much different from the pictures in the breed photo books.
Anyone who has been involved in a dog breed for many years, especially in Rescue, should be trusted when they give the opinion that this dog is probably one of their breed. Sometimes it's impossible to be certain, eg it can be very hard to be certain when distinguishing Giant Schnauzer from Bouvier, but most prospective adopters who like and are suited to either of these breeds will also be fine with the other one.
My own philosophy is "if in doubt, bail it out" because the dog would certainly prefer to remain alive and to have a chance at a loving home. And if it looks Bouvish and acts Bouvish, I know one of my waiting adopters will be delighted to adopt it.
 
For those of you who didn't take a Constitutional Law course, the reference in the second verse is to the famous statement of Supreme Court Justice Potter Stewart in Jacobellis v Ohio, 1964 that he could not define hard core obscenity "but I know it when I see it".