I agree with Mr. Peachy, giving human characteristics to non-human things. In my age, when I was in shool, using he or she for the animal was the wrong answer. Howerver, to classify the sex of the animals, using he or she is alright. It is called social acceptance.

To start, use only "it". You only use "he/she" if you are familiar with that animal, such as your pet. Compare BRSwartz's examples: there was a personal connection to the horse and the cat, but none with the raccoon. Using "he/she" for animals (and objects) is called anthropomorphism: giving human characteristics to non-human things.

Yes, you can, especially if it a specific animal like the horse that we both are looking at / know about or a pet cat or dog. "He's the best horse, I've ever ridden." "My cat is neurotic. She needs some mediation." If you don't know the gender, use "it:. "The raccoon was hit while it was walking across the road. "

no , l am a chinese girl it is wrong in china but l do not konw how to speak it in Enghish

I think no you can't ,cause you need to use IT for animals not he or she