I would say yes, to a limited degree, for a limited time, sometimes.

So I have a number of outdoor cats, and there was one time I went outside and one of my cats had died. Idek from what. His brother was just right beside him, sniffing him, trying to get him to move. I was like ooooh, this isn't good. I quickly grabbed the dead cat & moved out of sight, buried him.

But that damn cat wouldn't let it go. For a good couple days, he just had this thousand yard stare & a sad moaning meow. He discovered death, he seemed to realize death applies to everyone. Himself included. It reminded me of my own epiphany when I was 7 or 8, I almost wanted to chuckle a bit, it's like yeah bro welcome to the club. Death is our shared fate. Just try not to fixate on it.

So my cat's limit was about 2 days. After that, he seemed to move on & he was back to being happy again. Some extra seafood, catnip, and pets helped coax him out of the slump.

“It’s so weird. I shit in the box, and then the next day it’s just, gone. Where does it go? Who is stealing my poop?”

I think my neighbours cat experiences existential dread if she hasn't eaten in 5 nanoseconds...

Cats can't read Hegel nor Nietzsche, so I say no, they can't experience existential dread.

I'd say no, knowledge that we will some day die is unique to humans.

They certainly experience ennui though.

every time they look at their food bowl, regardless of how full it is

Outside of the occasional startle, no. The cat idle routine is very low level, not much going on there at all.

Since they are the land spirit of dread I don’t think they can.

Yes I think, certainly every single time I move some furniture.

Yes

This should answer your question.

Sigh. It's morning. Again.

No. But they do wonder if they should buy a boat.

Furball ennui

Maybe. But Scooter is experiencing the immediate need for long pats on the back.

No but they can experience existential fear (first time I took one of my cats on Holiday).

Of COURSE they do. Hell they feel existential dread towards things that aren't even there. Its just that their body language is so different from ours, that we don't usually recognize it.

Hell just staring into an unfamiliar cat's eyes can give it a case of the screaming jibblies.