Muslims are the dogs in this analogy... or maybe Syrians in general regardless of religion are the dogs.
We love dogs as long as they are not rapid. In context, Carson was clearly not putting down the refugees as a group. He was positing that the vetting to week out the chaff from the wheat should be most rigorous.
Carson is a mess, in my opinion, but this particular bullet against him is shooting blanks, and the press characterization of it, including CNN, which had the spin that Carson was saying the refugees are "rapid dogs," and that's it without further characterization (although to their credit they did show the entire clip which clearly impeached their characterization), is most unfair and wrong.
