Yes, you can certainly refer to animals as 'he' or 'she'. Not only beloved pets, but also wily foxes, sturdy bulls, speedy racehorses, cute fluffy bunnies....we use gendered pronouns for all sorts of animals.

In the United States, it depends entirely on how the person is thinking about the animal. "He" and "she" are considered respectful, "it" is considered cold. "He" and "she" are usually used when the sex is known. A rooster (male chicken) is "he." A hen (female chicken) is "she." "It" is used when the sex is not known, particularly if the animal is considered to be a pest, or verminous. Thus, for most of us, a spider is usually "it" even if we suspect it is female. "A spider! Ugh! Kill it!" However, a naturalist who admires spiders, or the novelist E. B. White in "Charlotte's Web," will say "she." "Watch her as she spins her orb web. It is amazing how she is able to get the spokes equally spaced." When we see a pet together with its owner, we do not want to use "it." We can ask, and the usual phrase is "Is it a 'he' or a 'she?'" Or, we may guess, and let the owner correct us: "What a cute puppy! He's adorable!" "It's a 'she.'"

Hi, Alisa. As a rule, the names of animals are replaced with a pronoun 'it"(singular form). However, if people are talking about their beloved pets, they can easily use "he" or "she" instead.

Yes, absolutely!

I think in older times, it was more common to address any animal as an "it". An example are the Narnia books from the 1950's, where if a passage mentions the word "horse", the pronoun of choice was often "it". If we know the horse's name and gender, then the book might refer to it as "he" or "she". But often Lewis still deferred to the usage of "it", even if if we know the horse's gender. Today, it is more common (in the U.S., at least) to refer to an animal as "he" or "she" if we know the gender. In the past, if you met a baby/ young child for the first time, and you're not sure of the gender, you could refer to "it". Now, calling a human an "it" is demeaning, and it forces us to enquire before we can correctly refer to the child.