@D00B @Tony @GolfCartLady @MrFuzzland OK so there's a few ways to go about this.

Weekly SQ injections of Ivermectin for 4 weeks usually does the trick. Some cats won't want to visit the vet this often, but it also takes application of treatment entirely out of your hands.

Prescription ear drops like Tresaderm work really well and is the fastest treatment, taking only like a week or two. But it's gonna be painful getting those drops in that ear, BUT it's designed so that you don't have to clean the ear after treatment. They DO have tresaderm and I believe some other otic topical drugs that are a one-and-done treatment of ear mites, I imagine it is more expensive though BUT the clinic can apply them for you :CirnoWink:

lots of fla/tick meds will actually kill and control ear mites. Basically any flea/tick med with selamectin, moxidectin, fluralaner, and saralaner will kill an ear mite infection. Chart related are some brands available; Keep in mind Bravecto, Nexguard, and Credelio are not labeled for ear mites, but they do kill ear mites. Most of these are topical. I would not suggest Seresto collars for this simply because there is a lot of human error with getting the right fit on and thus not getting enough of the dose, BUT it is a good budget option. These are one & done treatments (and preventatives), but you WILL need to clean the ears after treatment, or the build up of mite crap will create a new problem.

Don't get the no name or never heard of over the counter shit, it's AIDS and some of it like Hartz is well known for killing animals. Also be careful with counterfeits; there have been a lot of counterfeit serestos that are killing pets.

Then there are some over-the-counter treatments (again, DO NOT get Hartz), just make absolutely sure you're reading the instructions carefully and the product is labeled for cats. Many of these treatments are not killing the incubating mite eggs, so you'll need to continue the treatments for at least a month to make sure you scorch the ear canal of mites. So for example if the instructions are to put 3-5 drops in affected ears once every 3 days for 2 weeks, up that to once every 3 days for 4 weeks. I would recommend a good ear cleaning after these treatments as well to be on the safe side.

If you are bringing the animal to a vet, do not clean the ears prior. We want to see that nastiness. Also do not clean the ears directly after a treatment, obviously you'll be taking the meds out.

Also keep an eye on aural hematomas. I've attached some pictures of a serious case and a more mild case. It can happen with ear infections; they shake their heads and break blood vessels and the ear swells up. It's a rather painful condition that, if not treated, turns into cauliflower ear where the ear is all crumpled and covered in scar tissue. It is treated with the cat sedated, incising the ear to drain fluid and stitching it back up.

I hope this helped!