Dogs are more disposable than people? And I love dogs, but I don't see why they would inherently deserve better treatment than a cow or pig, and honestly if you oppose mistreatment of animals, than the cow or pig is probably suffering a hell of a lot more than the dog in this scenario.
Edit: https://xkcd.com/2368/ Lol, guilty, but if you want to talk about the moral imperative of vegetarianism than I am willing to listen.