You are right - I am sure that pets, animals in general, become secondary in a war. Look, you mention films. It's not for nothing that animals usually have no place in dystopian scenarios. Individual animal beings still clinging to life there seem out of place and anachronistic.
Du hast recht - ich bin sicher, daß Haustiere, Tiere allgemein, in einem Krieg zur Nebensache werden. Schau, Du erwähnst Filme. Nicht umsonst haben in dystopischen Szenarien Tiere meist keinen Platz. Einzelne Tierwesen, die sich dort noch ans Leben klammern, wirken fehl am Platze und anachronistisch.
In dystopian scenarios, depending on the scenario, maybe only wild animals can survive. No domestic animal would do that. Not without people. Therefore, on the one hand, the domestication of animals, and even more - the genetic selection of animals and the creation of new species is monstrous and selfish.
Well, that's not the point now, I know. I really hope that after such great cataclysms, people will realize and start thinking differently, start doing different things and change their lives.