The caller is not interested in the number of pets in the country or even in reducing the number of pets in shelters. The caller is interested in controlling Rush and making sure that Rush does not have to much freedom or too many dogs. He will be happy if Rush is restricted, even if this results in more pet overpopulation, because he is really interested in controlling the behavior of others.
Surely if Rush were to breed his young dog, he would be the prototypical proud pet papa, and would talk incessantly (more than golf!) about his new puppies. How many of his twenty million listeners are going to hear that and run out and pick up a dog from the shelter? How much will this reduce the numbers of unwanted pets? Rush, by being free to do what he wants, would have the very effect the caller claimed that he cared about. But, at the end of the day, that is not really what the caller cared about.
Similarly with taxes. You can prove, over and over again, that tax cuts for all, and particularly for the "rich", will increase revenue to the treasury. It works every time it is tried. But at the end of the day, the people who claim to care about reducing the deficit and increasing revenues will insist on tax hikes, because what they really care about is class warfare, and taking away from those they consider to have too much. The important thing is the resentment, the class envy. The important thing is that the rich be made to suffer, even if it reduces revenue to the government and hurts the poor.
STOP SPENDING! STOP SPENDING! STOP SPENDING!!!