Just get a titer test. And if vet tries to charge in the 1-200$ range - find a new vet. This should be a nominal charge in the $40 range
In fact if your vet still subscribes to annual shots may be time to look elsewhere.
He is your friend, your partner, your defender, your dog. You are his life, his love, his leader. He will be yours, faithful and true, to the last beat of his heart. You owe it to him to be worthy of such devotion. - Unknown