Am I abnormal for being cold to my friends, but easily soft to animals and not caring for others, even if they are my friends?

It shouldn't be your own problem, if I were to say there is one, it should be that you are too introverted. In fact, I have had the same feeling as you, the reason why you have pity on kittens and puppies their emotions because you feel from the heart that they are vulnerable and need your care. To put it in a way you don't like to hear: you probably feel that you are in an extremely similar situation to them, and need the same attention from others.

I assume you are an only child? Only children are more prone to this phenomenon of yours. I'm an only child too, and since I was a kid I've always played alone, at most with the kids in the hutongs. Sometimes I think I'm not autistic anymore. But in the future, we still have to go out into the society and come into contact with people, and we should still learn to communicate with people. Even if you think you're fine on your own, you still need to learn to get along with people! As for not caring about your friends, I'm going to go out on a limb and ask: do you really think of them as friends from the bottom of your heart? Do you just think of them as people who keep you company? People who are with you every day may not always be friends!