People who do this kind of thing will do the same thing to other living creatures—like people. The lives of Cats and Dogs are of relatively little importance compared to human life, but weeding out those who kill and torture either one is the issue for civilized society.
For instance, Dennis Lynn Rader, aka BTK (bind, torture and kill), tortured and killed dogs and cats in his youth. That did not stop him from killing 10 people in Wichita, KS, over a period of 17 years.