[triceratops]

Cool, so what are you going to do with all the hundreds of millions of pet animals that already exist?

> Similar reasoning, the idea is to cut down the downstream demand so we're able to cut down the upstream one

That's an inaccurate, backwards analogy. The accurate analogy would be "my pet eats only mango cores, so I'm going to buy the mango even though its from another continent". Which is patently untrue. Pet food demand doesn't drive human meat demand - human meat demand makes pet food cheap and plentiful. Cutting human meat demand would drive up the price of pet food (because there are fewer castoff materials available) and lead to people re-evaluating how many pets they can/should have. Alternatively, it may also lead to investments in healthy animal-free pet foods, similar to fake meat for humans.

Since you're so concerned about the environmental impact of pets, consider also that for many people, their pets are surrogate children. Presumably if they couldn't have pets they might have actual children, which is far more destructive to the environment.