Are ear infections contagious?

I feel like this is such a dumb question but I'm freaking out. I have a feeling this may all be in my imagination, especially since I'm in that "waiting period" on the cats' insurance.

The lady that lives upstairs has a kitty that is close to 20 years old. She just took her to the vet recently because she was scratching a lot and she has a really bad inner-ear infection apparently. She scratches and when she does this head-shaking thing, you can almost hear a rattle.

I SWEAR I'm seeing the same thing in EVERY ONE OF MY CATS. I'm probably just paranoid and seeing/hearing things that are not there, or they were doing the whole time. I can't imagine every last one of them would have the same thing,

Anyway, it's just a general question. Her kitty sometimes comes down to visit, and Oliver and Pea-Pea like to go upstairs quite a bit.

I have had ear infections and URI's in my house.  None of my other cats ever caught an ear infection from another family member.  My oldest cat had severe ear infections in both ears along with ear mites and a URI when she was a kitten.  She shared the URI but not the ear mites or ear infection.

Hopefully someone with more experience can provide further insight.

Are your cats other wise acting normal?  You have been through a lot lately so I understand your concern.  There is no such thing as a dumb question when it comes to our furkids.

Oh definitely normal otherwise. Still crazy and tornadic.

I don't think ear infections are contagious, but ear mites sure are. If you are concerned, you can take one of your cats in when the pet insurance comes in to see if that's the problem. If it isn't ear mites, then you don't need to take the others in.

No, ear infections are not contagious.

Ear mites are, but would have to be the reason for the infection.

Her kitty has had her poor ears dug into quite a bit the last two vet visits, and she had no mites. So no mites from her. No fleas, I've checked. Sara's a flea magnet, if any of them had it, she'd have it. She's snuck out in the middle of winter (which she was younger) when there was snow out and somehow got fleas.

I think I'm just over-reacting. But I really wanted to make sure that kind of thing (ear infection) was not contagious. I don't think any cat I've ever had has had an ear infection. I'm trying to remember, but can't think of one. The closest I can think of was when my cat Tiger had an ear tumor, and his head had that same rattle, but obviously that wasn't something contagious.