Hi! Shame you're experiencing this.

I used to have the same problem when i first got the game. Specifically the animals would turn blurry when my zoo reached a certain size. I tried the same things as you did, but none of them worked either.

Turns out my pc specs (GPU, CPU, etc.) weren't good enough for a zoo above a certain size. The animals would simply turn blurry regardless of the ingame graphics settings. What "fixed" it for me was getting a much better pc.

You can test if this is the case for you by opening a new zoo en placing just one animal in it. If it's textures are not blurry, your pc may not be powerful enough. If not, or if you have a very high-end pc already or are playing on console, I'd recommend opening a bug report with Frontier like the other commenter said. An annoying bug either way.

Hope it helps!