CCC 2415-2418 in the 7th commandment section concerns this. Note, it is under the 7th commandment (thou shalt not steal) not the 5th commandment (thou shalt not kill) because animals are not people.
Animals are essentially good because they're made good by God.
Animals are God's creatures. He surrounds them with his providential care. By their mere existence they bless him and give him glory.
Man has a duty to look after animals
God entrusted animals to the stewardship of those whom he created in his own image. Hence it is legitimate to use animals for food and clothing. They may be domesticated to help man in his work and leisure.
Mankind is justified in benefiting from using them as a means to and end (where this would be illicit use for other people)
Medical and scientific experimentation on animals is a morally acceptable practice if it remains within reasonable limits and contributes to caring for or saving human lives.
The Catholic Church is against cruelty to animals for it's own sake.
It is contrary to human dignity to cause animals to suffer or die needlessly.
And she is also against the practice of affluent people who take up resources that would otherwise go towards alleviating human suffering to take care of pets or other animals.
It is likewise unworthy to spend money on them that should as a priority go to the relief of human misery. One can love animals; one should not direct to them the affection due only to persons.