think of Companion Animals as gifts to societies elite and most trusted. Whomever does want to buy one is vetted and approved. When an Animal is classified as a Companion only their future owner can reclassify them as Meat and even then they have soul rights to it.

They are also subject to strict, sometimes random, health checks to ensure the health and stability of the Companion Animal, there's leeway of course but a healthy Companion Animal makes the System look good.