Like I said, it's literally all about how it's presented to us in the narrative. This is Neil Druckmann without the guy who according to him, used to make suggestions so that the stories wouldn't be as dark. "Humanity is doomed" can work into the overall theme of Hate.
You see my main point then. Infected animals in games are straight up rare.
I don't think we ever got an official explanation of how cordyceps jumped to humans anyway. If it is as grounded as the rest of the game, its likely that it was a man-made-mistake that led to this, and that means animals are completely up for grabs.
Also, I don't know why some folks thinks bloaters are "stretching" things so much, when they are explained in a way that makes a lot of sense. After becoming clickers, most of them will eventually die without eating / spreading, but the ones who survive this huge change continue to grow into the massive heaps. Makes enough sense if you think about how fungi spread, and why they aren't as common as the other kinds of infected.
Days Gone is the last game to have done infected animals, and I think with the way they handled it was just "stronger" and "scarier sounding" which is fine but...
The infected in TLOU become runners, stalkers, and end up completely blind - resorting to echolocation - right? I imagine they things animals could turn into would be supremely scary. Especially if there are bloater versions of said animals.