The reasons why a dog keeps shaking its head despite having clean ears:

1. It is probably caused by ringworm on its ears, and it often scratches them with its legs. It is best to clean its ears, spray them with medicine and wait for recovery.

2. After a dog is scratched by himself, it will become very itchy when it heals, which will cause it to shake its head constantly. It is best to put an anti-licking collar on it to prevent it from scratching. Scratching again, resulting in new wounds.

3. If a foreign object enters the dog’s ears, or the skin is too dry, it will also cause the dog to shake its head and use its legs to scratch the ears. It is best to remove the foreign object in time. , and add more water to it.

4. It may be caused by fleas, lice, mites and other parasites on the dog’s head.

5. It may also be caused by water in the dog's ear canal, fungal infection and other factors. It is recommended that the owner carefully check the dog's head and surroundings for abnormalities.