Dog & Cat Ear Infections: Cleaning, Treatment & Why They Keep Coming Back
Ear infections are painful, frustrating and often misunderstood. A dirty-looking ear is not necessarily an infected ear—and an infected ear usually needs more than cleaning. Understanding what is actually happening inside the ear canal is the key to choosing the right treatment and preventing the problem from returning.
The most important distinction: ear cleaner removes wax, discharge and inflammatory debris. Medication treats the bacteria, yeast and inflammation causing the infection. Cleaning can make treatment more effective, but cleaning alone generally does not cure an established bacterial or yeast ear infection.
At Desert Forest Animal Hospital in Cave Creek, ear disease is a frequent reason dogs and cats come in for dermatology care. Some pets experience one isolated episode. Others seem to develop infection after infection despite repeated medications.
The difference often comes down to whether we are simply treating what is growing in the ear today—or also identifying why the ear became inflamed enough for that overgrowth to occur in the first place.
Signs of an Ear Infection in Dogs and Cats
Ear infections can look very different from one patient to another. Common signs include:
- Frequent head shaking
- Scratching at one or both ears
- Rubbing the head or ear against furniture or carpet
- Redness inside the ear canal
- Brown, yellow, tan, black or pus-like discharge
- Unusual or strong ear odor
- Pain when the ear is touched
- Swelling of the ear canal
- Thickened skin around the ear opening
- Holding one ear differently from the other
- Reluctance to have the head touched
A dog or cat does not need to have every sign on this list. Some ears are profoundly inflamed even when there is relatively little visible debris.
What Is Otitis Externa?
The medical term for inflammation of the external ear canal is otitis externa.
One important point is often missed: otitis externa is inflammation, not automatically infection. Bacteria and yeast frequently become secondary problems after something else has changed the ear canal’s normal environment.
According to the Merck Veterinary Manual’s professional review of otitis externa , small populations of gram-positive cocci and yeast can normally inhabit the ears of dogs and cats. Changes in the ear canal can allow those organisms—or other bacteria—to overgrow and become clinically important.
Factors that may initiate or perpetuate ear disease include allergies, parasites, foreign material, excess moisture, anatomic changes, chronic inflammation, masses, polyps and middle-ear disease.
Cocci, Rods and Yeast: What We See Under the Microscope
Looking at ear debris under the microscope is called ear cytology. It is one of the most useful tests we can perform for an infected ear because it tells us what is present today.
Cocci
Cocci are round bacteria. Staphylococcal and streptococcal organisms are common examples encountered on ear cytology.
Many uncomplicated bacterial external-ear infections dominated by cocci respond well to appropriately selected topical medication.
Yeast
Malassezia yeast is a common contributor to canine and feline otitis.
Yeast-associated ears may be red, itchy, odorous and produce brown or waxy discharge. Treatment generally includes appropriate topical antifungal therapy and control of inflammation.
Rod-Shaped Bacteria
Rods deserve additional attention because they can represent organisms such as Pseudomonas, Proteus, E. coli or other gram-negative bacteria.
Rod infections are often associated with more complicated, chronic or previously treated ears and may require culture, special cleaning strategies and longer treatment.
How Veterinarians Diagnose an Ear Infection
A good ear examination involves more than looking at the discharge.
Depending on the individual patient, evaluation may include:
- A medical and dermatologic history
- Examination of the ear flap and surrounding skin
- Otoscopic examination of the ear canal
- Assessment of canal redness, swelling and narrowing
- Evaluation of the tympanic membrane—the eardrum—when it can be safely visualized
- Ear cytology
- Culture and susceptibility testing in selected cases
- Investigation of underlying allergy or skin disease
- Additional imaging or middle-ear evaluation when deeper disease is suspected
The AAHA Management of Allergic Skin Diseases in Dogs and Cats Guidelines emphasize ear cytology when ear disease is present and specifically identify recurrent otitis externa as a common manifestation of underlying allergic disease.
When Is an Ear Culture Needed?
Not every ear infection requires culture.
Cytology often gives us enough information to select treatment for an uncomplicated first infection. Culture and antimicrobial susceptibility testing become more important when we encounter:
- Large numbers of rod-shaped bacteria
- Suspected Pseudomonas infection
- Severe infection
- Chronic or recurrent infection
- An ear that has failed appropriate previous therapy
- Concern for antimicrobial resistance
- Possible middle-ear involvement
Culture tells us which bacteria can be grown from the sample and which antimicrobial drugs they are susceptible or resistant to. It is used alongside—not instead of—cytology and the physical examination.
How to Clean a Dog’s Ear Correctly
Cleaning can be a very important part of treating otitis because wax, pus and inflammatory debris can physically interfere with topical medication reaching the skin lining the ear canal.
But there is an equally important rule:
A clean-looking ear can still contain bacteria or yeast on cytology.
If your veterinarian has instructed you to clean the ear at home, the basic technique is:
Avoid pushing cotton swabs deep into the canal. They can push material farther down and may traumatize an already inflamed ear.
What Kind of Ear Cleaner Should You Use?
For routine home cleaning when cleaning is medically appropriate, we generally want a veterinary-approved drying or astringent ear cleanser selected for the individual ear rather than water or a homemade solution.
A drying/astringent product can help remove debris and reduce residual moisture—two things that are useful in many uncomplicated external-ear problems.
However, not every diseased ear should receive the same cleaner.
For example, the Merck Veterinary Manual notes that tris-EDTA-containing cleansers may be useful when rod-shaped bacteria are present, while certain detergents should not be used when the tympanic membrane is ruptured.
This is also why we do not recommend routinely pouring hydrogen peroxide, alcohol, vinegar solutions or essential-oil mixtures into an infected ear.
Should I Clean the Ear Before My Veterinary Appointment?
If you have an appointment specifically for an ear problem, ask the veterinary team before performing a thorough cleaning immediately beforehand.
Your veterinarian may want to collect the existing material for cytology before it is removed.
Ear Cleaner vs. Ear Medication: They Have Different Jobs
Ear Cleaner
- Removes wax
- Removes discharge
- Helps clear inflammatory debris
- May help dry the canal when an appropriate drying cleaner is used
- Can improve contact between medication and the ear canal
Ear Medication
- Treats susceptible bacteria
- Treats yeast when an antifungal is included
- Reduces inflammation when a corticosteroid is included
- Helps relieve swelling, pain and itching
- Must be selected for the actual condition being treated
Many veterinary ear medications combine an antibacterial agent, antifungal agent and corticosteroid. The appropriate combination depends on what is present on cytology, the severity of inflammation and the condition of the eardrum.
At-Home Ear Drops vs. Long-Acting “Leave-In” Medication
There are two broad ways topical ear medication may be delivered.
At-Home Ear Medication
Some medications are drops or ointments that the owner administers once or more daily for a prescribed period.
These medications can be very effective, but success depends heavily on:
- Applying the correct amount
- Getting the medication into the canal rather than only onto the ear flap
- Using it at the prescribed frequency
- Continuing for the prescribed duration
- Returning for the recommended recheck
Long-Acting or “Leave-In” Ear Medication
Some veterinary medications are placed into the ear and designed to remain there for an extended period.
These products can be especially helpful for pets who strongly resist home medication or when a family’s schedule makes frequent dosing difficult.
Do not clean the ear unless your veterinarian specifically tells you to do so. Cleaning may remove medication that is intended to remain inside the canal. You should also prevent water from entering the ear during bathing or swimming unless your veterinarian has told you otherwise.
Exact instructions vary by medication, so follow the instructions provided for the specific product your pet receives.
Does My Dog Need Oral Antibiotics for an Ear Infection?
Usually, not for an uncomplicated infection confined to the external ear canal.
Topical ear medication delivers medication directly where it is needed and is generally the foundation of therapy for bacterial and yeast otitis externa.
The Merck Veterinary Manual specifically notes that systemic antimicrobials are generally not required for uncomplicated otitis externa and become much more relevant when otitis media—middle-ear involvement—is suspected.
This approach is also consistent with the AAFP/AAHA Antimicrobial Stewardship Guidelines , which emphasize accurate diagnosis and judicious antimicrobial use.
The goal is to use the right medication, at the right site, for the right organism, for the appropriate duration.
Why Would a Veterinarian Prescribe Oral Steroids for an Ear Infection?
Sometimes infection is only part of the problem.
Severe inflammation can cause an ear canal to become extremely swollen and narrow. This is called stenosis.
A severely stenotic ear presents several problems:
- Medication may not reach the deeper canal
- Debris becomes trapped
- The eardrum may be impossible to visualize
- Cleaning becomes more difficult
- The pet may be extremely painful
In selected cases, a veterinarian may use a short course of systemic corticosteroid therapy to reduce marked inflammation and help open the canal.
Many topical ear medications also contain a corticosteroid because reducing inflammation, swelling and discomfort is an important part of successful otitis treatment.
How Long Does an Ear Infection Take to Treat?
There is no single treatment duration that is correct for every ear.
Some uncomplicated infections are initially treated for approximately one to two weeks depending on the medication being used. However, an ear that looks better after two weeks is not necessarily cytologically normal.
Current professional veterinary guidance notes that many acute bacterial or yeast infections require approximately two to four weeks to reach true resolution, while chronic, resistant or middle-ear infections may require considerably longer.
| Type of Ear Problem | Typical Consideration |
|---|---|
| Uncomplicated acute otitis externa | Often improves rapidly, but treatment continues until clinical and cytologic resolution. |
| Yeast or coccal infection | May resolve within a few weeks when appropriately treated and the underlying cause is controlled. |
| Rod-shaped bacterial infection | Often requires closer monitoring, sometimes culture, and may need a longer course. |
| Chronic or recurrent ear disease | May require weeks to months plus management of the underlying cause. |
| Middle-ear disease | Requires a different diagnostic and treatment strategy and frequently longer therapy. |
Why the Recheck Appointment Matters
One of the most common reasons an ear infection appears to “come right back” is that treatment was stopped when the ear looked and felt better—but before the infection had actually resolved.
Pain and itching may improve before the bacterial or yeast population has returned to an acceptable level.
At a recheck appointment, we can reassess:
- Redness
- Swelling
- Discharge
- Pain
- Canal narrowing
- The eardrum when visible
- Repeat ear cytology
This tells us whether medication can stop, needs to continue, or needs to change.
Why Does My Dog Keep Getting Ear Infections?
A dog that has infection after infection usually has more going on than bad luck.
1. Allergies
Allergic skin disease is one of the most important underlying causes of recurrent otitis in dogs.
In some dogs, recurrent ear inflammation may be one of the most obvious—or even the only obvious—signs of allergy.
AAHA’s allergic skin disease guidelines specifically emphasize recurrent otitis as an important manifestation of allergic disease.
If your dog repeatedly develops itchy ears, paw licking, skin infections, redness or seasonal flares, learn more about our pet allergy evaluation and treatment in Cave Creek .
2. Water and Moisture in the Ear
Swimming, bathing and chronic moisture can alter the microenvironment inside the ear canal and contribute to microbial overgrowth in susceptible pets.
This does not mean every dog’s ears need aggressive cleaning after every bath. For dogs with a history of moisture-associated otitis, your veterinarian may recommend an individualized preventive cleaning plan using an appropriate drying cleaner once active infection has resolved.
3. Treatment Was Stopped Too Soon
The dog stops scratching. The odor disappears. The ear looks much better.
Unfortunately, that does not prove the organisms are gone.
This is why prescribed treatment duration and recheck cytology matter.
4. The Previous Medication Did Not Match the Problem
Different microorganisms require different treatment.
A medication that worked beautifully for a previous yeast infection may not be appropriate for a new rod-shaped bacterial infection.
This is also why using leftover ear medication from a previous episode is not a good substitute for a current examination and cytology.
5. The Underlying Cause Was Never Controlled
Recurrent otitis can also be associated with:
- Environmental allergies
- Food-associated allergic disease
- Ear mites
- Foreign material in the ear
- Chronic moisture
- Anatomic narrowing
- Polyps or masses
- Chronic proliferative changes
- Middle-ear disease
Our veterinary dermatology service evaluates recurrent skin, coat and ear problems with the goal of treating both the immediate infection and the condition that allowed it to recur.
What Can Happen If an Ear Infection Is Left Untreated?
A neglected ear infection can progress far beyond itching and odor.
Aural Hematoma
Violent head shaking and scratching can contribute to an aural hematoma—a collection of blood and fluid inside the ear flap.
The ear may suddenly become thick, swollen and fluid-filled.
Treatment requires controlling the underlying itchy or painful ear disease. Depending on the individual hematoma, management may involve drainage, medication or surgery.
The Merck Veterinary Manual review of auricular hematomas identifies head shaking and scratching associated with otitis externa as an important contributing factor.
Permanent Narrowing of the Ear Canal
Repeated inflammation can cause tissue inside the ear canal to become progressively thickened, scarred and narrowed.
As the canal narrows, medication penetration becomes more difficult and moisture and debris become easier to trap—creating a cycle in which each infection becomes harder to treat.
Middle-Ear Disease
Infection and inflammation can extend deeper into the middle ear.
Signs that increase concern for otitis media or interna can include:
- Repeated external-ear infections that will not resolve
- Significant pain
- Pain when opening the mouth
- Head tilt
- Loss of balance
- Nystagmus—rapid involuntary eye movement
- Facial nerve abnormalities
- Hearing changes
You can read more about deeper ear disease in the Merck Veterinary Manual review of otitis media and interna .
End-Stage Ear Disease and TECA Surgery
In severe end-stage chronic ear disease, the canal can become so permanently diseased that medical management can no longer keep the patient comfortable.
These patients may ultimately require a surgery called a total ear canal ablation, or TECA, generally combined with surgical treatment of the tympanic bulla.
This is major surgery.
Preventing chronic otitis from progressing to this stage is one reason early diagnosis, appropriate medication, rechecks and long-term control of underlying allergy are so important.
What About Ear Infections in Cats?
Cats develop many of the same bacterial and yeast problems as dogs, but the list of underlying causes can look different.
In cats, veterinarians may be particularly attentive to:
- Ear mites, especially in younger cats or cats with relevant exposure
- Inflammatory polyps
- Foreign material
- Allergic skin disease
- Bacterial or yeast overgrowth
- Middle-ear disease
- Masses in older cats
Dark debris is sometimes assumed to mean ear mites, but appearance alone cannot reliably tell us what is in the ear. Microscopy and examination are much more useful than guessing based on color.
Cats can also be particularly sensitive to handling when their ears hurt. Dr. Quinn Bauer is a Fear Free Certified veterinarian at Desert Forest Animal Hospital, and our team incorporates gentle, behavior-aware handling whenever the medical situation permits.
Learn more about our Fear Free veterinary care in Cave Creek .
When Is an Ear Infection Urgent?
Most uncomplicated external-ear infections are uncomfortable but not immediately life-threatening. Some signs warrant faster evaluation.
- Severe or rapidly worsening ear pain
- Marked swelling
- Significant bleeding or pus-like discharge
- A sudden head tilt
- Loss of balance or repeated falling
- Rapid involuntary eye movements
- Facial drooping or inability to blink normally
- Difficulty walking
- Severe lethargy or systemic illness
During regular hospital hours, Desert Forest Animal Hospital provides same-day urgent veterinary care in Cave Creek when staffing, current case volume and the pet’s medical needs allow.
If your pet has severe neurologic signs or another life-threatening problem, a 24-hour emergency hospital may be the safest destination.
What If My Pet Is Too Painful to Let Anyone Examine the Ear?
A badly infected ear can hurt considerably.
Forcing an otoscope or aggressive cleaning into a severely painful ear is not necessarily the safest or most humane approach.
Depending on the patient, the veterinarian may first address pain and inflammation, use modified handling techniques, or recommend sedation so the ear can be examined and cleaned more safely.
Our goal is not simply to “get the procedure done.” It is to obtain the information and treatment the patient needs while avoiding unnecessary fear and pain whenever circumstances allow.
Preventing the Next Ear Infection
Once an active infection is resolved, prevention depends on understanding what caused or perpetuated it.
A prevention plan might involve:
- Managing underlying allergies
- Using an appropriate maintenance ear cleaner
- Keeping susceptible ears dry after swimming or bathing
- Monitoring dogs with recurrent seasonal ear disease
- Completing the full prescribed medication course
- Returning for recommended cytology rechecks
- Avoiding unnecessary or inappropriate antibiotic use
- Investigating repeated infections rather than simply repeating the same medication indefinitely
If allergies appear to be driving the problem, treating the infection without controlling the allergy is likely to provide only temporary relief.
Frequently Asked Questions About Dog & Cat Ear Infections
Can I treat my dog’s ear infection at home?
An established ear infection should be evaluated before treatment because yeast, cocci, rod-shaped bacteria, mites, foreign material and allergic inflammation require different approaches. Using leftover medication or a home remedy can delay correct treatment and may be unsafe if the eardrum is damaged.
Can I just clean my dog’s infected ear?
Usually not. Cleaning removes wax, discharge and debris, but established bacterial or yeast infections generally require appropriate medication. Think of cleaning as preparing the ear for treatment rather than replacing treatment.
What should I use to clean my dog’s ears?
When routine cleaning is appropriate, use the veterinary-recommended cleaner selected for your pet’s ear. A drying or astringent veterinary cleanser is often useful for routine external-ear cleaning, but severely inflamed ears, rod infections or ears with a damaged eardrum may require a different product.
Can I use hydrogen peroxide in my dog’s ear?
We do not recommend routinely using hydrogen peroxide in an infected ear. Inflamed tissue can be sensitive, and the appropriate cleaning solution depends partly on the condition of the canal and eardrum.
Why does my dog’s ear infection keep coming back?
Common reasons include underlying allergies, water or chronic moisture, stopping medication before true resolution, treatment that did not match the organisms present, resistant bacteria, canal narrowing, foreign material or middle-ear disease.
Are recurrent dog ear infections caused by allergies?
Very often. Allergic skin disease is one of the major underlying causes of recurrent otitis externa in dogs. In some patients, recurring ear inflammation may be one of the most obvious signs of allergy.
Does my dog need oral antibiotics for an ear infection?
Not usually for an uncomplicated infection confined to the external ear canal. Topical therapy is generally preferred. Systemic antibiotics become more relevant when deeper infection such as otitis media is suspected or another specific medical indication exists.
How long should I treat my dog’s ear infection?
It depends on the organism, medication, severity and whether deeper disease is present. Some uncomplicated infections are initially treated for roughly one to two weeks, but many acute infections require two to four weeks for true clinical and cytologic resolution. Chronic infections can take considerably longer.
Why does my veterinarian want to recheck the ear if it looks better?
Symptoms may improve before the infection is completely resolved. Repeat examination and cytology help determine whether medication can safely stop or needs to continue.
What does rod bacteria in a dog’s ear mean?
Rod-shaped bacteria can include organisms such as Pseudomonas, Proteus and E. coli. They are often associated with more complicated infections and may prompt culture, susceptibility testing or a more intensive treatment plan.
Can my dog swim while being treated for an ear infection?
Usually it is best to keep water out of an infected ear unless your veterinarian gives different instructions. This is especially important if a long-acting leave-in medication has been placed in the ear.
Can a dog ear infection cause an ear hematoma?
Yes. Pain and itching can trigger forceful head shaking and scratching, which can contribute to formation of an aural hematoma in the ear flap. Some hematomas require procedural or surgical treatment in addition to treatment of the underlying ear disease.
Can chronic ear infections require surgery?
In severe end-stage chronic ear disease, permanent canal changes may make medical management ineffective. Some patients ultimately require total ear canal ablation, or TECA, generally with surgical treatment of the middle ear.
Dog & Cat Ear Infection Treatment in Cave Creek, Carefree & North Scottsdale
Desert Forest Animal Hospital provides veterinary dermatology and ear care for dogs and cats from Cave Creek, Carefree, Desert Mountain, North Scottsdale, Tatum Ranch, Desert Hills and surrounding North Valley communities.
Depending on your pet’s condition, evaluation may include otoscopic examination, ear cytology, culture when indicated, treatment of bacterial or yeast infection and investigation of allergies or other underlying causes.
Pet owners nearby can also learn more about our veterinary care near Carefree and veterinary care near Desert Mountain and North Scottsdale.
When additional medical information is needed, our hospital also provides in-house veterinary diagnostics and blood work as medically appropriate.
Is Your Dog or Cat Shaking, Scratching or Developing Ear Odor?
An ear infection is easier to treat before chronic inflammation causes severe swelling, narrowing or deeper disease. If your pet is uncomfortable, has discharge or odor, or keeps getting repeat ear infections, schedule an examination rather than starting leftover medication from a previous episode.
Desert Forest Animal Hospital
6554 E Cave Creek Road
Cave Creek, AZ 85331
Veterinary References & Further Reading
This article was developed using current veterinary clinical guidance and authoritative professional references, including:
- Merck Veterinary Manual — Otitis Externa in Animals
- Merck Veterinary Manual — Otitis Media and Interna in Animals
- Merck Veterinary Manual — Auricular Hematomas in Animals
- American Animal Hospital Association — Management of Allergic Skin Diseases in Dogs and Cats Guidelines
- AAFP/AAHA — Antimicrobial Stewardship Guidelines
Medical review: Bryan Hayter, DVM — Owner & Medical Director, Desert Forest Animal Hospital. Learn more about Desert Forest Animal Hospital and our veterinary team.
Last medically reviewed: October 2026
This article provides general educational information about ear disease in dogs and cats. It cannot determine the cause or severity of an individual pet’s symptoms and is not a substitute for a veterinary examination, diagnosis or individualized treatment plan. Do not place medication or cleaning solution into a severely painful ear or an ear with a potentially damaged eardrum without veterinary guidance.