Cat Ear Infection Signs: Discharge, Odor, Scratching and Head Shaking
Common cat ear infection signs include repeated scratching, head shaking, redness, pain, abnormal odor and increased discharge. These changes can occur with inflammation of the outer ear canal, but their presence does not tell you whether the underlying problem is ear mites, bacteria, yeast, allergy, a foreign object, a polyp or another ear disorder. Merck lists parasites, foreign material and allergies among primary causes of feline ear inflammation, with bacteria and yeast sometimes contributing secondarily.
Changes involving balance, hearing or head position deserve additional attention because disease affecting the middle or inner ear can involve the structures responsible for hearing and equilibrium.
Direct Answer
Scratching, head shaking, redness, swelling, pain, odor and abnormal discharge are important signs that a cat’s ear needs attention. However, these symptoms cannot identify the cause on their own. A veterinarian may need an otoscopic examination and microscopic evaluation of ear debris to look for mites, bacteria or yeast and to check for foreign material, polyps or eardrum problems.
What a Healthy Ear Generally Looks Like
A healthy ear should not have persistent redness, swelling, foul odor, obvious pain or a large accumulation of abnormal discharge. Merck recommends regularly observing feline ears for changes in colour, moisture, discharge, scabs and other abnormalities. It also notes that healthy cats generally do not need routine ear cleaning unless a veterinarian recommends it.
Some wax can be present without indicating disease. The more useful question is whether the ear has changed from the cat’s normal appearance or has become uncomfortable.
Scratching
Occasional scratching does not automatically indicate an ear infection, but persistent or intense scratching suggests irritation or discomfort.
A cat may scratch because of:
- ear mites
- inflammation of the ear canal
- allergy
- infection
- debris or foreign material
- another itchy skin problem
Cornell advises owners not to probe into persistently itchy ears to find the cause themselves.
Repeated scratching can also damage the ear flap and contribute to an aural hematoma, where blood accumulates between the skin and cartilage.
Head Shaking
A cat shaking its head repeatedly may be trying to respond to itching, pain, discharge or another uncomfortable sensation inside the ear.
Head shaking is a recognised sign of otitis externa and can also occur when middle-ear disease or an inflammatory polyp is present.
Record:
- which direction the cat turns its head
- whether one ear seems more affected
- how frequently shaking occurs
- whether scratching occurs at the same time
Head shaking becomes more concerning when a head tilt or balance problem develops.
Redness
Redness of the ear flap or visible canal indicates inflammation but does not identify the cause.
Otitis externa can produce:
- redness
- swelling
- itching
- discharge
- pain
and these findings can occur whether the original trigger was parasitic, allergic, foreign material or another inflammatory problem.
Redness accompanied by discharge, pain or repeated head shaking warrants veterinary examination.
Pain
Ear disease can be painful.
A painful cat may:
- pull away when the ear is approached
- flatten the ear
- resist being touched around the head
- become irritable
- cry or react when the ear is handled
- resist opening its mouth if deeper structures are affected
Merck notes that painful or heavily obstructed ears sometimes require sedation or anesthesia for a safe otoscopic examination.
Do not restrain a painful cat simply to look deeper into the canal.
Odor
If a cat’s ear smells bad, the odor is worth recording, particularly when it is new or accompanied by discharge or inflammation.
Malodor is a recognised sign of otitis externa, but smell alone cannot tell you whether bacteria, yeast, mites or another underlying condition is responsible.
Strong odor together with persistent discharge should be investigated instead of treated with deodorising products.
Dark Discharge
A dark discharge in a cat’s ear is commonly associated in people’s minds with ear mites, but it should not be diagnosed visually.
Ear mites can produce dark waxy or crusted debris and may cause intense scratching and head shaking. Cornell describes dark accumulated wax and mite debris as a typical finding, but confirmation can involve otoscopic or microscopic examination.
Other ear problems can also produce brown or dark material.
Therefore:
dark discharge ≠ confirmed ear mites
Yellow Discharge
Yellow, cream-coloured or pus-like discharge can occur with inflammatory or infectious ear disease, but its colour is not sufficient to determine which organism or underlying condition is involved.
For example, inflammatory ear polyps can be associated with ear discharge, including purulent material in some cases.
A veterinarian may use cytology to examine ear debris for bacteria, yeast and inflammatory cells rather than choosing treatment from colour alone.
Crusting
Crusts may occur:
- around the opening of the ear
- on the pinna
- alongside hair loss
- after repeated scratching
Mites and other inflammatory skin conditions can produce crusting around the ears, while self-trauma may make lesions worse.
Photograph crusts before repeatedly cleaning them away so you can show their original distribution to your veterinarian.
Ear Mites
The question of cat ear mites vs infection cannot be answered simply by comparing discharge photographs.
Ear-mite infestation may cause:
- scratching
- head shaking
- dark waxy or crusted debris
- inflammation
but bacterial, yeast and other ear problems can produce overlapping signs.
A veterinarian can inspect the ear with an otoscope and examine debris microscopically for mites.
Do not use an ear-mite medication merely because the discharge looks dark.
Bacterial or Yeast Involvement
Bacteria and yeast may be involved in otitis externa, but they are often only part of the problem.
Merck notes that parasites, foreign objects and allergies may initiate inflammation, after which bacteria or yeast can complicate the ear disease. Identifying those underlying factors is important because treating only the microbes may allow the problem to return.
Microscopic ear cytology helps the veterinarian decide whether bacteria or yeast are present in clinically significant numbers.
Polyps
Inflammatory polyps are growths that can involve the feline middle ear, external ear canal or nasopharyngeal area.
Ear-related polyps can be associated with:
- head shaking
- ear discharge
- head tilt
- balance problems
- abnormal eye or facial signs
depending on how far the polyp extends.
An otoscope may reveal a polyp in the ear canal, while deeper disease can require imaging such as CT or MRI.
Persistent one-sided ear disease is one reason a veterinarian may look for abnormal tissue rather than repeatedly treating it as a routine infection.
Foreign Material
Material lodged inside the ear canal can trigger inflammation and discomfort.
Merck includes foreign objects among causes of external-ear inflammation. Otoscopic examination can help identify foreign material that cannot be seen by looking only at the ear opening.
Do not insert tweezers or other objects into the canal to retrieve something you suspect is inside.
Allergies
Allergic skin disease can contribute to recurring ear inflammation in some cats.
The important point is that ear symptoms do not prove allergy. Parasites, infection, foreign material and structural disease may produce the same signs.
If itching occurs elsewhere as well, use Pawnium’s Cat Itching but No Fleas guide to document the broader skin pattern rather than assuming the ears alone identify the trigger.
One Ear Versus Both
Whether one or both ears are affected is useful diagnostic information.
Merck notes that otitis externa can affect one or both ears. Persistent one-sided obstruction may lead a veterinarian to investigate possibilities such as a foreign body, polyp or other abnormal tissue more closely.
Left ear: normal / affected
Right ear: normal / affected
Do not assume bilateral disease means allergy or unilateral disease means a foreign object. Distribution is only one clue.
Head Tilt
A new head tilt needs more attention than uncomplicated wax or mild scratching.
Middle- and inner-ear disease can cause the cat to tilt its head toward the affected side. Inflammatory polyps can also produce head tilt when deeper ear structures are involved.
Contact a veterinarian promptly if head tilt appears, particularly when accompanied by difficulty walking or abnormal eye movements.
Balance Problems
The inner ear contains structures responsible for balance.
When inner-ear disease develops, a cat may:
- become uncoordinated
- lean or fall
- have difficulty standing
- walk abnormally
- show abnormal eye movements
Merck states that balance, walking or jumping problems with suspected ear disease warrant prompt veterinary examination.
These signs should not be treated as a routine outer-ear infection at home.
Hearing Changes
Reduced response to sound can occur when ear disease affects sound transmission or deeper ear structures.
Middle- or inner-ear inflammation can be associated with impaired hearing or deafness, and longstanding severe ear disease may lead to permanent damage.
Hearing changes are particularly useful to mention if they appear suddenly or occur alongside discharge, head tilt or balance problems.
Why Discharge Colour Cannot Diagnose the Cause
The appearance of debris is useful for description, not diagnosis.
Dark material may occur with ear mites, while brown, black or yellow discharge can also be seen with otitis externa. Different causes can therefore overlap visually.
Veterinary diagnosis may involve:
- examination of both ears
- otoscopy
- cytology
- microscopic mite examination
- evaluation of the eardrum
- investigation for polyps or foreign material
- imaging when middle or inner ear disease is suspected
Avoid captions or charts that say:
Black = mites
Yellow = bacteria
Brown = yeast
Those shortcuts are not reliable diagnostic rules.
What Owners Can Observe Safely
You can record information without inserting anything into the ear.
Look from the outside for:
- Redness
- Swelling
- Visible discharge
- Crusting
- Odor
- Hair loss around the ear
- Scratching
- Head shaking
- Whether one or both ears are involved
- Head tilt
- Balance changes
- Hearing changes
Cornell recommends routinely looking for swelling, discharge, discoloration and debris but specifically advises against probing into a persistently itchy ear.
Photograph each ear in similar lighting if the problem changes over several days.
What Not to Put in the Ear
Do not experiment with home treatments before you know what is happening inside the canal.
Avoid:
- hydrogen peroxide
- rubbing alcohol
- essential oils
- vinegar-based home mixtures
- medication prescribed to another pet
- dog ear medication unless your veterinarian confirms it is appropriate for your cat
Hydrogen peroxide can irritate an inflamed canal, and veterinary guidance also warns that alcohol-containing cleaners may be irritating when the canal is inflamed or ulcerated.
The ASPCA advises against directly applying concentrated essential oils to pets because exposure can cause health problems.
Ear medications also differ depending on what is causing the problem and whether the eardrum is intact. Use products recommended for that individual cat rather than borrowing another animal’s treatment.
Do Not Insert Cotton Swabs Deep Into the Ear
Cotton-tipped applicators can push material farther into the canal and risk trauma to the ear canal or eardrum.
If cleaning is recommended, have the veterinary team show you the appropriate method and product.
When Veterinary Care Is Needed
Arrange veterinary examination when your cat has:
- persistent scratching
- repeated head shaking
- new or increasing discharge
- foul odor
- redness or swelling
- obvious pain
- recurring ear problems
- discharge from only one ear that persists
- reduced hearing
- suspected foreign material
- symptoms that return after treatment
Merck recommends identifying the underlying cause because simply treating secondary bacteria or yeast without addressing parasites, allergy, foreign material or other factors can allow otitis to recur.
Seek Prompt Veterinary Care for Deeper-Ear Signs
Contact a veterinarian promptly when ear symptoms occur with:
- head tilt
- loss of balance
- difficulty standing or walking
- circling
- abnormal side-to-side eye movements
- facial drooping
- sudden marked hearing changes
These findings can occur with middle- or inner-ear disease or polyps affecting deeper structures.
FAQs
What are the most common signs of an ear infection in cats?
Common signs include scratching, head shaking, redness, swelling, pain, odor and increased discharge. These symptoms indicate ear irritation or inflammation but do not identify the underlying cause.
Does dark discharge mean my cat has ear mites?
Not necessarily. Ear mites frequently produce dark waxy debris, but other forms of otitis can create similar-looking discharge. Mites are better confirmed through otoscopic or microscopic examination.
Why does my cat’s ear smell bad?
Odor can occur when the ear canal is inflamed and may accompany bacterial, yeast or other ear disease. Smell alone cannot identify which organism or underlying cause is responsible.
Why is my cat shaking its head but the ear looks clean?
Problems deeper in the ear canal may not be visible from the outside. Foreign material, inflammation, mites, middle-ear disease or polyps are among issues a veterinarian may investigate with an otoscope and other tests.
Is head tilt an ear-infection symptom?
It can occur with middle- or inner-ear disease and with inflammatory polyps affecting deeper ear structures. A new head tilt, particularly with poor balance or walking difficulty, deserves prompt veterinary examination.
Can I clean my cat’s infected ear with peroxide or alcohol?
Do not use them as routine home treatments. Hydrogen peroxide and alcohol-containing cleaners can irritate an already inflamed ear canal. Ask your veterinarian which cleaner, if any, is appropriate after the ear has been examined.
