No, "~* LCPLIC3 *~ <3", you are a textbook sociopath for reacting this way!
Since when are animals defenseless? When my ancestors were being chased by sabertooth tigers it was every species for itself, but now that we've won we're the bad guy! Humbug! And animals in the wild torture and kill their prey all the time, even when they're not hungry. It's called sport. (I guess Animal Planet doesn't mention that for its own interests.)
Since when is lack of compassion for animals abnormal? We eat them all the time! And don't give me any bull about the need for nourishment making it excusable while the need for whatever psychological advantage cruelty to animals brings being inexcusable. Most ancient religions involved some form of animal sacrifice! Animal testing is pretty much the basis of modern science and medicine! Who died and made your subjective sense of value to rule with an iron fist over everyone else?
The overwhelming majority of felines alive today are alive as pets for our pleasure. Little house kitties evolved to be cute and cuddly. Most people will enjoy treating them compassionately, but some will prefer sick sadistic torture. Maybe this person believes that to avoid the "bad karma" for killing one cat she needs to donate enough money to a pet shelter to rescue 10 cats that would otherwise be killed, as they routinely are? And in a free market the concept of karma would have an actual financial benefit: a person might be ostracized for doing bad things to animals, but forgiven for doing good.
I can relate to the anger you describe because I feel the same anger whenever I see a YouTube video of cops roughing up a protester, or other abuses by the government. Now there is a case of sadism vs helplessness! I can relate to the "don't taze me bro" guy. I cannot relate to being a cat - nor a mouse that that cat might have had for breakfast, killing it in a very similar way. Human values apply to human situations. Applying them to rocks, plants, dolls, or subhuman animals is a logical fallacy. As I have said above: rights come from economic necessity, not your subjective sense of repugnance or pity!
Using your emotions to justify an irrational act against another human being: that's exactly what sociopaths do. That lady, on the other hand - who knows... She might be using kitty torture to deal with the stress of working long hours to find the cure for cancer. It's a more disgusting means of relaxing than smoking or kiddy porn, I agree. Though not as disgusting as watching Oprah.