Can you be specific? I anticipate that the people you are thinking of are heretics. I mean specifically that they deviate from dogmas of the church, not any colloquial definition.
The Catholic position is grounded in natural law theory. The telos of the sexual organs is essentially procreative; deny the procreative end and sex becomes incomprehensible. To use sexual organs in a manner that _intentionally_ works against their end is to intentionally frustrate their end. To intentionally thwart the operation of your faculties and misuse them is immoral and therefore contradicts one's fulfillment and actualization as a human being.
Calling people cattle for living in accordance with the procreative end of sexual intercourse, which is the ultimate end of sexual intercourse, is nasty, if not irrational. Before you do so, I suggest you acquaint yourself[0] with the actual position held and defended by the Catholic Church.
[0] https://www.catholic.com/magazine/print-edition/lets-think-a...
This is a straw man assertion…
The church is perfectly fine with promiscuity, artificial insemination, sterilization etc. among cattle or pets.
The same behaviors they tell humans are immoral, because they think humans aren’t just cattle.