The question is, do you feel empathy for humans?
I tend to have more empathy for animals than for humans, because, in my mind, most companion animals have the ability that many humans lack: To love unconditionally. It is that forgiving nature that blows me away and makes me love them so.
Perhaps you never had a companion animal. Perhaps you never read a story, or learned the amazing things that companion animals do for their humans.
I don't know why you don't have empathy, but I know how you CAN get empathy: Go to your local animal rescue organization and offer to perhaps sit with the animals, read to them, pet them. As you become more familiar with them, hopefully you'll begin to feel more kindness and empathy for them. Read books and stories about the brave cats and dogs who have saved the lives of their people - like the cat who fought off a dog who was attacking the little boy she lived with; the dogs who every day put their lives on the line to help the police catch wrongdoers every day; or the pot-bellied pig who went outside, running to anyone she could to get them to follow her and help her human who was inside, suffering from a massive heart attack; the pets that help their humans every day to avoid seizures or warn them when their blood sugar is too low.