Why Your Dog Won't Stop Scratching Their Ears

By Emiel Maddens  ·  Reviewed in consultation with licensed veterinary professionals  ·  Updated June 2026  ·  10 min read

Photo by Tima Miroshnichenko on Pexels

Few things concern a dog owner more than watching their pet relentlessly scratch, paw at, and shake their head because of ear discomfort. Ear problems are among the most common reasons dogs visit the veterinarian, with otitis externa (inflammation of the outer ear canal) affecting an estimated 10 to 20 percent of dogs at some point in their lives. The repeated scratching can cause secondary trauma to the ear, including hematomas (blood blisters) on the ear flap, excoriation of the skin around the ear, and even self-inflicted wounds from frantic pawing.

While the scratching itself is distressing, it is a symptom rather than a diagnosis. Dogs scratch their ears because something inside the ear canal is causing irritation, pain, or itching, and determining what that something is requires a systematic diagnostic approach. The list of possible causes ranges from relatively simple issues like ear mites and foreign bodies to complex, chronic conditions like allergic otitis and middle ear infection. The underlying cause determines the treatment approach, the likely duration of treatment, and whether the problem is likely to recur.

This comprehensive guide covers the anatomy of the dog ear, the most common causes of chronic ear scratching, the diagnostic process, treatment approaches for each cause, and strategies for preventing recurrent ear problems. Whether your dog has developed ear scratching for the first time or has been battling chronic ear issues for years, understanding the complete picture will help you work more effectively with your veterinarian to resolve the problem.

Understanding Dog Ear Anatomy

The anatomy of the canine ear canal differs significantly from the human ear and helps explain why dogs are so prone to ear problems. The dog's external ear canal is L-shaped, consisting of a vertical canal that descends from the ear opening and then makes a near-90-degree turn to become the horizontal canal, which leads to the tympanic membrane (eardrum). This L-shaped configuration creates a natural pocket where debris, wax, moisture, and microorganisms can accumulate, as gravity does not easily drain material out of the horizontal portion of the canal.

The ear canal is lined with skin that contains sebaceous glands (which produce waxy cerumen), apocrine glands (which produce a watery secretion), and hair follicles. The relative density of these structures varies between breeds, with some breeds having particularly abundant ceruminous glands that produce large amounts of earwax. The skin lining the ear canal is contiguous with the skin of the body, which means that skin diseases affecting the rest of the body, particularly allergic skin disease, also affect the ear canal lining.

Breed Predispositions

Certain ear conformations make some breeds more susceptible to ear problems. Dogs with pendulous (floppy) ears, such as Cocker Spaniels, Basset Hounds, and Bloodhounds, have reduced air circulation within the ear canal, creating a warm, humid environment that favors microbial growth. Breeds with hairy ear canals, such as Poodles and Schnauzers, can have hair that traps debris and moisture within the canal. Dogs with narrow or stenotic ear canals, such as Shar-Peis, have less room for drainage and are prone to canal swelling that further restricts airflow. Breeds with large, open ear canals, such as German Shepherds, have better ventilation but may be more vulnerable to foreign body entry.

Understanding these anatomical factors is important because they explain why ear problems are so common in dogs, why certain breeds are disproportionately affected, and why simply treating the current infection without addressing predisposing factors often leads to recurrence. A comprehensive approach to ear health must consider the individual dog's ear anatomy alongside the specific cause of the current problem.

Ear Infections: The Most Common Cause of Scratching

Bacterial Ear Infections

Bacterial otitis externa is one of the most common ear conditions in dogs. The bacteria most frequently involved include Staphylococcus pseudintermedius, Pseudomonas aeruginosa, Proteus species, and Escherichia coli. Staphylococcus is typically associated with initial or uncomplicated infections, while Pseudomonas and other gram-negative bacteria are more commonly found in chronic, treatment-resistant cases. Bacterial infections produce a purulent (pus-containing) discharge that may be yellow, green, or cream-colored, often with an unpleasant odor. The ear canal appears red, swollen, and painful, and affected dogs may resist having their ears examined or touched.

Yeast Ear Infections

Malassezia pachydermatis is the most common yeast organism involved in canine ear infections and thrives in the warm, moist, oil-rich environment of the ear canal. Yeast otitis typically produces a characteristic dark brown to black, waxy discharge with a distinctive musty or sweet odor that many veterinarians can recognize by smell alone. The ear canal appears mildly to moderately inflamed, and while yeast infections cause significant itching, they tend to be less painful than bacterial infections. Yeast infections are strongly associated with allergic skin disease and often occur alongside bacterial infections in mixed infections.

Mixed Infections

Many ear infections involve both bacteria and yeast simultaneously, creating a mixed infection that requires treatment targeting both types of organisms. Mixed infections are particularly common in chronic or recurrent otitis, where the ear canal environment has been altered by prolonged inflammation, previous treatments, and changes in the local microbiome. Identifying all organisms present through cytological examination of ear discharge is essential for selecting the right combination of antimicrobial treatments. Treating only the bacterial component while ignoring yeast, or vice versa, will result in incomplete resolution and rapid recurrence.

It is critical to understand that ear infections in dogs are almost never a primary disease. In the vast majority of cases, there is an underlying condition, most commonly allergic skin disease, that has altered the ear canal environment and allowed microorganisms to overgrow. Treating the infection with ear medications will resolve the current episode, but without addressing the underlying cause, new infections will continue to develop. This is why recurrent ear infections are so common and why a comprehensive diagnostic approach is essential for long-term management.

Persistent ear scratching is one of the most common reasons dogs visit the veterinarian.

Photo by Anya Prygunova on Unsplash

Allergies: The Root Cause of Most Recurrent Ear Problems

Allergic skin disease is the underlying cause of recurrent ear infections in an estimated 50 to 80 percent of affected dogs. Both atopic dermatitis (environmental allergies) and food allergies can manifest primarily or exclusively as otitis, sometimes with no other visible skin symptoms. In these dogs, the allergic inflammation affects the skin lining the ear canal, causing swelling, increased cerumen production, and changes in the local immune environment that favor bacterial and yeast overgrowth. Some dogs with allergic otitis may have concurrent skin symptoms such as paw licking, face rubbing, and ventral itching, while others may only show ear signs.

Atopic Dermatitis and Ears

Environmental allergies are the most common allergic cause of ear problems in dogs. Allergens such as pollens, dust mites, mold spores, and animal dander trigger an IgE-mediated inflammatory response in the ear canal skin, just as they do in the skin elsewhere on the body. Atopic ear disease often shows a seasonal pattern initially, with ear flare-ups occurring during specific pollen seasons, though over time the condition may become year-round as the dog develops sensitivities to additional allergens. Bilateral (both ears) involvement is typical of allergic otitis, as the allergic process affects both ear canals equally.

Food Allergies and Ears

Food allergies are the second most common allergic cause of chronic ear disease and can be particularly challenging to diagnose because the only reliable diagnostic method is an elimination diet trial lasting eight to twelve weeks. Dogs with food-allergic otitis tend to have year-round ear problems without seasonal variation, which can help distinguish food allergy from environmental allergy. The most common food allergens in dogs are proteins including beef, chicken, dairy, wheat, and soy. Blood tests marketed for food allergy diagnosis are not considered reliable by veterinary dermatologists, and a properly conducted elimination diet remains the gold standard for diagnosis.

Managing allergic ear disease requires both treating acute infections when they occur and implementing long-term allergy management to prevent recurrence. This may include immunotherapy (allergy shots or sublingual drops) for environmental allergies, dietary management for food allergies, daily anti-itch medications to reduce overall allergic inflammation, and regular ear cleaning to maintain a healthy ear canal environment. Without ongoing allergy management, ear infections will continue to recur despite successful treatment of individual episodes.

Ear Mites and Other Parasites

Ear mites (Otodectes cynotis) are a common cause of ear scratching in puppies and in dogs that have contact with cats, but they are a relatively uncommon cause of otitis in adult dogs that live exclusively with other dogs. Ear mites are tiny parasites that live on the surface of the ear canal skin, feeding on cellular debris and ear wax. They cause intense itching and produce a characteristic dry, dark brown to black, coffee ground-like debris in the ear canals. The debris is composed of mite waste products, dried blood, and ear wax, and its appearance is often distinctive enough to raise suspicion for mites on physical examination.

Diagnosis of ear mites is confirmed by microscopic examination of ear debris, where the mites and their eggs can be visualized. Treatment is straightforward, with modern isoxazoline-class antiparasitic medications (such as fluralaner, sarolaner, and afoxolaner) providing effective single-dose treatment. Topical ear mite treatments, such as ivermectin-based ear drops, are also available. All animals in the household should be treated simultaneously, as ear mites are highly contagious between animals and can temporarily survive in the environment.

Other parasitic causes of ear scratching are less common but worth considering in certain situations. Demodex mites can occasionally inhabit the ear canals and cause otitis. Sarcoptic mange mites have a predilection for the ear margins (edges of the ear flap) and can cause intense itching of the ears and ear tips, though this is technically an external ear problem rather than an ear canal issue. Ticks can occasionally attach inside the ear canal, causing localized irritation and scratching. Fly strike, where flies bite the tips of erect ears, can cause crusting and itching, particularly in outdoor dogs during warm months.

Foreign Bodies, Polyps, and Structural Causes

Foreign Bodies

Foreign bodies lodged in the ear canal are an important cause of acute-onset, unilateral (one-sided) ear scratching and head shaking. Grass awns (foxtails) are the most common ear canal foreign bodies, and they can work their way deep into the canal, sometimes penetrating the tympanic membrane and entering the middle ear. Other foreign bodies include grass seeds, small twigs, sand, and rarely, insects. The onset of symptoms is typically sudden and dramatic, with intense head shaking, pawing at the affected ear, and a head tilt toward the affected side. Diagnosis requires otoscopic examination, and removal usually requires sedation or general anesthesia.

Aural Polyps

Inflammatory polyps (also called nasopharyngeal polyps) are benign growths that arise from the mucosa of the middle ear or Eustachian tube and can extend into the ear canal, causing obstruction, secondary infection, and chronic scratching. While more common in cats, aural polyps do occur in dogs, particularly in younger animals. Signs include chronic, unilateral ear discharge and scratching that responds poorly to standard ear infection treatment. Polyps can sometimes be visualized during otoscopic examination as pink, smooth, pedunculated masses emerging from the depth of the ear canal. Treatment involves surgical removal of the polyp, sometimes requiring a more extensive surgical approach to address the stalk in the middle ear.

Ear Canal Narrowing (Stenosis)

Chronic or recurrent ear infections can cause permanent changes in the ear canal structure, including thickening and fibrosis of the canal walls, proliferative tissue growth, and calcification of the cartilage. These changes progressively narrow the ear canal, reducing airflow, trapping moisture and debris, and creating an environment where infections become increasingly difficult to treat. In severe cases, the ear canal can become completely occluded. Dogs with end-stage ear canal stenosis may require total ear canal ablation (TECA), a surgical procedure that removes the entire ear canal and associated diseased tissue.

Early and effective management of ear infections helps prevent the structural changes that lead to stenosis. This is one of the most important reasons to address recurrent ear problems aggressively and to identify and manage the underlying cause. Once the ear canal has undergone significant structural changes, they are generally irreversible, and the management options become more limited and more invasive.

Diagnosing the Cause of Ear Scratching

Otoscopic Examination

An otoscopic examination, where the veterinarian uses a lighted cone-shaped instrument to look into the ear canal, is fundamental to evaluating ear problems. This examination allows visualization of the ear canal walls (assessing inflammation, stenosis, and masses), the character and amount of discharge, the presence of foreign bodies, and the integrity of the tympanic membrane (eardrum). In some cases, sedation may be necessary for a thorough otoscopic examination, particularly if the dog is in significant pain, if deep examination is needed, or if the canal is too inflamed or narrow for safe examination while awake.

Ear Cytology

Cytological examination of ear discharge is one of the most important diagnostic tests for ear problems and should be performed in virtually every case. A sample of ear discharge is collected on a cotton-tipped applicator, rolled onto a microscope slide, heat-fixed, stained, and examined under the microscope. Cytology reveals the type and relative numbers of bacteria (cocci vs. rods), the presence of yeast organisms, inflammatory cells, and occasionally parasites or abnormal cells. This information directly guides treatment decisions, as the choice of ear medication depends on whether the infection involves bacteria, yeast, or both, and whether rod-shaped bacteria (which may be Pseudomonas and require different antibiotics) are present.

Culture and Sensitivity

For chronic, recurrent, or treatment-resistant ear infections, particularly those involving rod-shaped bacteria on cytology, bacterial culture and sensitivity testing is recommended. This test identifies the specific bacterial species and determines which antibiotics will effectively kill them. Culture-guided antibiotic selection is especially important for Pseudomonas infections, which are inherently resistant to many commonly used antibiotics and can be very difficult to eradicate. The sample for culture should ideally be collected before initiating ear medication to avoid false negative results.

Investigating Underlying Causes

For dogs with recurrent ear infections, investigating the underlying cause is as important as treating the current infection. This investigation may include allergy testing (intradermal or serum panels), food elimination diet trials, thyroid function testing, and evaluation for other predisposing factors such as excessive ear hair, swimming habits, or conformational abnormalities. In some cases, advanced imaging (CT scan) of the ears and skull may be recommended to evaluate for middle ear disease, bony changes, or deep-seated problems that are not visible on otoscopic examination.

Treatment Approaches for Ear Problems

Ear Cleaning

Proper ear cleaning is a fundamental component of ear infection treatment and ongoing maintenance. Cleaning removes accumulated discharge, debris, and biofilm from the ear canal, allowing topical medications to contact the canal wall and be effective. A veterinary-approved ear cleanser is instilled into the ear canal, the base of the ear is massaged to distribute the cleanser throughout the canal, and the dog is allowed to shake their head to expel the loosened debris. The outer ear is then gently wiped clean. Cleaning should be performed before each application of ear medication. The type of cleanser matters, as some contain antibacterial or antifungal ingredients, some contain drying agents, and some are designed specifically for heavy wax removal.

Topical Ear Medications

Most ear infections are treated primarily with topical ear medications that are instilled directly into the ear canal. These medications typically contain a combination of antibacterial, antifungal, and anti-inflammatory ingredients. Common antibacterial agents include fluoroquinolones (enrofloxacin, marbofloxacin), aminoglycosides (gentamicin, neomycin), and polymyxin B. Antifungal components include miconazole, clotrimazole, and nystatin. The anti-inflammatory component, usually a corticosteroid such as dexamethasone or betamethasone, is crucial for reducing the inflammation, swelling, and itching that drive the scratching behavior. Treatment courses typically last two to three weeks, and it is important to complete the full prescribed course even if symptoms improve earlier.

Systemic Medications

In cases of severe, chronic, or deep-seated ear infections, systemic (oral) medications may be needed alongside topical treatment. Systemic antibiotics are indicated when the infection has extended beyond the ear canal into the middle ear, when the ear canal is too swollen or painful for effective topical treatment, or when specific organisms requiring systemic therapy (such as Pseudomonas) are involved. Systemic antifungal medications may be needed for severe yeast overgrowth. Oral anti-inflammatory or anti-itch medications can help manage the discomfort and reduce scratching while the topical medications take effect.

Long-Term Management

For dogs with allergy-driven recurrent ear infections, long-term management is essential to prevent future episodes. This typically includes regular ear cleaning (weekly or biweekly, depending on the individual dog), ongoing allergy management through immunotherapy, dietary control, or anti-itch medications, and prompt treatment of early signs of ear flare-ups before they develop into full-blown infections. Some veterinary dermatologists recommend maintenance ear medications used periodically to prevent infection recurrence in highly susceptible dogs. The goal is to keep the ear canal environment healthy enough that opportunistic organisms cannot establish infections.

When Ear Scratching Signals Deeper Issues

Middle and Inner Ear Disease

When infection extends beyond the outer ear canal through the tympanic membrane into the middle ear (otitis media) or inner ear (otitis interna), the condition becomes significantly more serious. Middle ear infection can cause chronic, deep-seated pain, purulent discharge, and head tilt. Inner ear infection affects the vestibular system, causing dramatic signs including loss of balance, circling, nystagmus (rapid, involuntary eye movements), and difficulty walking. Dogs with suspected middle or inner ear infection require prompt veterinary attention, advanced imaging (CT scan), and often prolonged courses of systemic antibiotics.

Aural Hematoma

An aural hematoma is a collection of blood within the ear flap (pinna) that develops when vigorous head shaking or ear scratching ruptures blood vessels within the cartilage. The ear flap becomes swollen, warm, and fluid-filled, often dramatically altering its appearance. While the hematoma itself is not dangerous, it indicates that the underlying ear problem is causing enough discomfort to drive violent head shaking, and both the hematoma and the ear condition need to be addressed. Hematomas are typically treated surgically (drainage and suturing to prevent refilling) or medically (drainage and corticosteroid injection), and the underlying ear problem must be treated simultaneously to prevent recurrence.

Chronic ear disease that is allowed to progress without adequate treatment can lead to permanent changes that significantly impact the dog's quality of life. These include irreversible ear canal stenosis (requiring surgical intervention), hearing loss from chronic middle ear disease or tympanic membrane damage, and chronic pain from calcified, narrowed ear canals. The message is clear: persistent ear scratching deserves thorough investigation and treatment, and addressing the underlying cause early provides the best chance for a good long-term outcome.

If your dog has been treated for ear infections multiple times without lasting resolution, or if the infections seem to clear up with medication only to return within weeks of stopping treatment, it is time to investigate the underlying cause more aggressively. Referral to a veterinary dermatologist may be warranted for dogs with chronic, recurrent ear infections. Dermatologists have specialized otoscopic equipment, including video otoscopy that allows deep cleaning and detailed examination under anesthesia, and extensive experience managing complex ear cases.

Why Your Dog Won't Stop Scratching Their Ears FAQ

Q: How do I know if my dog has an ear infection?

Common signs of an ear infection in dogs include scratching or pawing at the ear, head shaking, a noticeable odor coming from the ear, visible discharge (which may be brown, yellow, or black), redness and swelling of the ear canal or ear flap, pain when the ear is touched, and head tilting toward the affected side. Some dogs with ear infections also rub their heads on furniture or the floor. If your dog is showing any of these signs, a veterinary examination with ear cytology is the most reliable way to confirm whether an infection is present and identify the specific organisms involved.

Q: Why does my dog keep getting ear infections?

Recurrent ear infections almost always indicate an underlying condition that has not been adequately addressed. The most common underlying cause is allergic skin disease, either environmental allergies (atopic dermatitis) or food allergies, which affects the ear canal lining and creates an environment favorable for bacterial and yeast overgrowth. Other contributing factors include ear conformation (floppy ears, narrow canals, excessive hair), swimming or bathing without ear protection, hormonal disorders like hypothyroidism, and immune suppression. Identifying and managing the underlying cause is the key to breaking the cycle of recurrent infections.

Q: Can ear infections cause hearing loss in dogs?

Yes, chronic or severe ear infections can cause hearing loss in dogs. Outer ear infections can impair hearing temporarily by causing canal swelling and discharge accumulation that blocks sound transmission. Middle ear infections can damage the ossicles (tiny bones that transmit sound) and the tympanic membrane. Inner ear infections can affect the cochlea, the organ responsible for converting sound into nerve signals. Chronic, untreated ear disease that leads to canal stenosis and calcification can also cause permanent conductive hearing loss. Early, effective treatment of ear infections helps prevent these complications.

Q: Are ear mites common in adult dogs?

Ear mites (Otodectes cynotis) are relatively uncommon in adult dogs compared to puppies and cats. While they do occur in adult dogs, particularly those with outdoor access, contact with cats, or living in multi-pet households, other causes such as allergic otitis, bacterial infections, and yeast infections are far more common in adult dogs. The characteristic dry, dark, coffee ground-like debris of ear mites can be mimicked by certain yeast infections, so microscopic confirmation of mites is important before starting treatment specifically for mites.

Q: Should I clean my dog's ears regularly?

Regular ear cleaning can be beneficial for dogs prone to ear problems, but it is not necessary for all dogs. Dogs with healthy ears that do not accumulate excessive wax or debris generally do not need routine cleaning. However, dogs with allergic ear disease, dogs with pendulous ears, dogs that swim frequently, and breeds predisposed to ear problems often benefit from weekly or biweekly cleaning with a veterinary-approved ear cleanser. Over-cleaning can actually cause irritation, so the frequency should be tailored to the individual dog's needs. Your veterinarian can recommend the appropriate cleaning schedule and product for your dog.

Q: Can food allergies cause ear infections in dogs?

Yes, food allergies are a well-recognized underlying cause of chronic and recurrent ear infections in dogs. In some food-allergic dogs, ear problems may be the only clinical sign, with no other visible skin symptoms. Food allergies cause inflammation in the ear canal lining, altering the local environment and predisposing to secondary bacterial and yeast infections. The only reliable way to diagnose food allergy is an elimination diet trial using a novel protein or hydrolyzed protein diet for eight to twelve weeks. If the ear infections resolve during the trial and return when the original diet is reintroduced, food allergy is confirmed.

Sources

Nuttall, T. & Bensignor, E. (2014). A pilot study to develop an analogue scale for assessment of the severity of otitis externa in dogs. Veterinary Dermatology, 25(3), 176-183.

Paterson, S. & Matyskiewicz, W. (2018). A study to evaluate the primary causes associated with Pseudomonas otitis in 60 dogs. Journal of Small Animal Practice, 59(4), 238-242.

Saridomichelakis, M.N., Farmaki, R., Leontides, L.S., & Koutinas, A.F. (2007). Aetiology of canine otitis externa: a retrospective study of 100 cases. Veterinary Dermatology, 18(5), 341-347.

Griffin, C.E. (2010). Otitis techniques to improve practice. Clinical Techniques in Small Animal Practice, 21(3), 96-105.

Miller, W.H., Griffin, C.E., & Campbell, K.L. (2013). Muller and Kirk's Small Animal Dermatology, 7th Edition. Elsevier.

Hensel, P., Santoro, D., Favrot, C., et al. (2015). Canine atopic dermatitis: detailed guidelines for diagnosis and allergen identification. BMC Veterinary Research, 11, 196.

Related Reading

• Ear Infection Recovery Timeline, What to expect during ear infection treatment
• Yeast Dermatitis in Dogs, How yeast contributes to ear and skin infections
• Allergy Testing in Dogs, Identifying the allergic triggers behind ear problems
• When to See a Vet Dermatologist, Specialist care for chronic ear conditions

Emiel Maddens

Founder of Vetified. Develops topical antifungal and antimicrobial formulations for companion animals. Vetified products are listed on DailyMed and manufactured through FDA-registered facilities in the United States.