When Jesus mentioned the "one flock, one shepherd," was he referring to the Catholic Church alone?

In John 10:16 Jesus says &quot;I have other sheep that are not of this fold; I must lead them too, and they will heed my voice. So there shall be one flock, one shepherd.&quot; Does that one flock mean the One Holy Apostolic Catholic Church or does that include all the other Protestant churches in the world? What does the Church teach? <br />