My rabbit has fur loss and flaky ears. Could it be Cheyletiella mites?

This could be due to Cheyletiella parasitovorax, a rabbit skin mite. It's characterized by by patchy fur loss with flaking on the back of a rabbit. I'd have Rueben seen by a vet to have this diagnosed and treated.

Binky may be suffering from mites, as may your other rabbit. Patchy fur loss with flaking along the rabbit's back is typical for the mite Cheyletiella parasitovorax, Your veterinarian may examine a sticky tape preparation or skin scraping under the microscope for the presence of mites, however, might sometimes not find any, even though they are present on the rabbit. Mites are usually eradicated easily. Classic treatment is with injectable or oral ivermectin, or a selamectin spot on given in treatments two weeks apart. As mites live in the environment of your rabbit, it is essential to thoroughly clean your rabbit's cage and disinfect areas after each treatment to control reinfestation, since fur and dander in the environment may contain mite eggs. You will need to treat all rabits in your household.

Rabbits can be treated for mites with ivermectin or revolution. I would however recommend taking Olaf to another vet to get the proper dosing. You do need to clean the cage every day for a least 1-2 weeks to help prevent re contamination from the mites. I hope that helps

That certainly looks like seborrhea to me. The most common cause of this type of symptom in rabbits is called a fur mite (cheyletiella). To treat or prevent these types of mites, the use of Revolution (a preventative marketed for dogs and cats) should be used. In order to determine if this is the cause definitively, a skin scraping would be needed. Sometimes, diagnosing these can be tricky even when you know exactly what you are looking for, so often it is better to just try and treat to see if there is any improvement.

These look like sticktight fleas. The best treatment is a drug called Revolution (the one used on cats). You will need to get his from your vet and they can give you the correct dosing. ( https://www.birdexoticsvet.com/small-mammal-vet )

Mites would be the most common reason for scratching, mites cannot be seen with the naked eye at all (only under the microscope). you might want to take him to the vet in order to get a treatment for mites.

Sometimes mites can be transmitted by commercial store-bought food or hay. You will need to take your rabbit to a veterinarian for an exam and proper diagnosis. The vet can then inject your rabbit with an acaricide that will get rid of the mites. You will also have to clean out thee cage thoroughly, wash it with bleach and rinse it well, and wash all toys and food and water containers in very hot water. Throw away the food and hay you have and buy new food with a long expiration date.