Can ear mites kill a cat?

Directly? No. Indirectly? Absolutely. Untreated ear mite infections can cause secondary infections that can then spread to the rest of the body and yes - eventually kill a cat. The mites basically set up house and lay eggs, grow and will perforate right through the ear drum. The cat's balance will also be off if this is in just one ear and he won't be able to walk straight.

Why are you asking this? So you have an excuse not to bother treating your poor suffering cat? How about the great deal of discomfort your cat is experiencing???? Get it to the freaking vet.

No but they can cause a lot of discomfort for your cat,ear mites can cause infection which is where problems can happen as infection can if left cause damage,the black stuff you see is actually the mites poop and which infection can be caused,

but as your getting your cat to the vets as soon as possible then you can avoid any complications,some vets will clean the ears while the cats under anaesthetic it depends on how bad a case of mites it is,so be prepared that this is a possibility,

our cat once had this and she was prescribed two types of drops and we were told one wouldn't work without the other,she recovered well with no long lasting affects from her experience,

Best of luck.

No, but they are terribly uncomfortable and can lead to partial or total hearing loss. They can also spread to other animals, and can lead to secondary ear infections left untreated. Treating them really isn't so hard! Revolution (which also treats fleas and ticks) kills them, and there are many other medications applied to the ear that kills them.