What’s actually causing it
PetMD groups feline ear trouble into a few repeating causes, and scratching is the shared symptom:
- Ear mites. Tiny, highly contagious parasites — the top cause in kittens and outdoor cats. Intense itch, head-shaking, and dark "coffee-ground" debris.
- Infection. Bacterial or yeast overgrowth brings a bad odor, thick discharge, and redness.
- Allergies. Itchy, inflamed ears that often come with skin or coat changes, and can tip into infection.
- Other. Foreign objects (grass, insects), polyps, hematomas from vigorous scratching, and rarely cancer.
Clues that hint at the cause
You can’t diagnose by eye, but the patterns differ. PetMD notes ear mites typically produce dark, crumbly coffee-ground debris and itch like crazy but usually don’t smell bad. Infections more often carry a foul odor and thicker discharge. Allergies tend to show up in other itchy spots too — the chin, paws, or base of the tail. A vet confirms with an otoscope and a quick ear swab.
Signs you need the vet now
Ear scratching is not something to wait out. PetMD lists signs that mean a prompt vet visit:
- Persistent scratching or head-shaking
- Debris, odor, redness, or swelling
- A head tilt or balance problems
- A swollen, puffed-up ear (a hematoma from scratching)
Untreated mites and infections can lead to eardrum damage or hearing loss, so earlier is better.
Treatment starts with a diagnosis
The golden rule: diagnose first. PetMD is clear that you cannot tell mites from infection by looking, so guessing wastes time and risks the ear. A vet will view the canal with an otoscope, check a swab under the microscope, and then prescribe the right fix — mite medication (often a monthly spot-on that also treats the whole household), antibiotics or antifungals for infection, or allergy management. Never push cotton swabs or home remedies deep into the ear.
Frequently asked questions
How do I know if my cat has ear mites vs an infection?
You can’t be sure without a vet — the two look similar. Mites usually mean dark, crumbly coffee-ground debris and intense itch without much smell; infections more often bring odor and thicker discharge. Only an otoscope and ear swab confirm it, so skip the guesswork.
Can I treat cat ear mites at home with olive oil?
No. Olive oil might soften debris but it does not kill mites, and ear mites need prescription parasite medication — often a spot-on that also treats every pet in the home, since mites spread easily. Home remedies delay real treatment and let the infestation worsen.
Why is my cat scratching one ear only?
One-sided scratching usually points to a local issue in that ear — a mite hotspot, a foreign object like a grass seed, an infection, or a polyp. Because it is focused, it is a clearer signal to have that ear examined rather than assuming it is just a habit.
Is ear scratching contagious to my other pets?
Ear mites are — they spread readily between cats and to dogs, which is why vets often treat every pet in the household at once. Infections and allergies are not contagious, but all three need a vet to tell them apart before you treat.