Cats may shake their heads as a part of regular grooming, which is entirely normal.
Itchy ears can cause head shaking; check for signs of ear problems
Foreign objects in the ear can lead to discomfort and head shaking
Ear infections can be a common cause of head shaking in cats
Ear mites and parasites may trigger head shaking; consult your vet
Allergies can irritate a cat's ears, prompting head shaking
If head shaking persists, consult a vet to rule out health issues