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Inflammation (Redness, Swelling) of the External Auditory Canal in Dogs

Author: Dr. med. vet. Gisa Löwe | Last modified: 06.11.2025

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Inflammation of the external auditory canal in dogs is a condition characterized by redness, swelling, and possibly pain and discharge in the area of the external auditory canal. This condition is also known as otitis externa.

Can Occur with the Following Diseases:

Basics and possible causes

The external auditory canal of a dog is L-shaped and consists of a vertical and a horizontal part. This anatomical structure makes it susceptible to the accumulation of moisture, dirt, and foreign bodies, which can cause inflammation. Inflammation occurs when the body’s immune systemThe immune system is the body's defense system against infectious agents such as bacteria, viruses, fungi, and parasites. It comprises a complex network of organs, cells, and molecules that work together to protect the body. responds to stimuli or damage, leading to increased blood flow and an accumulation of immune cellsImmune cells are specialized cells of the immune system that help to identify and fight pathogens and foreign substances. These include leukocytes such as lymphocytes (T cells and B cells), macrophages, and dendritic cells. in the affected area.

There are several possible causes for inflammation of the external auditory canal in dogs. A common cause is allergies, which can be triggered by environmental factors such as pollen, dust, or food. Allergies cause the immune systemThe immune system is the body's defense system against infectious agents such as bacteria, viruses, fungi, and parasites. It comprises a complex network of organs, cells, and molecules that work together to protect the body. to overreact and cause inflammations. Infections caused by bacteriaBacteria are microscopic, single-celled organisms that exist in almost every environment on Earth. Some types of bacteria are beneficial or even essential to life, while others can cause disease. or yeast are also common triggers. These microorganisms find ideal growth conditions in a warm, moist ear canal.

Other causes can be foreign bodies such as awns or small branches that get into the ear canal and cause irritation there. Injuries to the ear canal or an excessive accumulation of earwax can also cause inflammations. Certain breeds, especially those with long, drooping ears, are particularly susceptible due to the reduced air circulation and moisture accumulation in the ear canal.

Typical accompanying symptoms

Redness and swelling: Often the first signs of inflammation, caused by increased blood flow and the accumulation of fluid in the affected area.
Itching: Dogs with otitis externa often scratch their ears or rub their head against objects to relieve the itching.
Unpleasant odor: An infectionAn infection is the colonization and multiplication of pathogens such as bacteria, viruses, fungi, or parasites in an organism, which often, but not always, leads to a disease. can cause a foul or yeasty odor in the ear that is easily recognizable to the owner.
Discharge from the ear: A yellowish, brownish, or even black discharge may come from the affected ear, indicating an infectionAn infection is the colonization and multiplication of pathogens such as bacteria, viruses, fungi, or parasites in an organism, which often, but not always, leads to a disease..
Pain: The dog may show pain when the affected ear is touched, such as by whining or pulling away.
Head shaking: Dogs with inflammation of the external auditory canal often shake their head to get rid of the irritation.
Hearing loss: In severe cases, the inflammation can impair hearing, which is manifested by a reduced reaction to noises.

When to visit the vet?

A visit to the veterinarian is urgently required if the symptoms of otitis externa persist or worsen for more than one to two days. It is particularly serious if the dog shows signs of severe pain, such as constant whining or avoiding touching the head. The appearance of blood in the discharge or a significant swelling of the entire ear area also require immediate veterinary assistance.

A visit to the veterinarian is also advisable if the dog repeatedly suffers from otitis externa, as this may indicate an underlying chronicChronic refers to a condition or disease that is long-lasting or permanent. Chronic diseases often develop slowly and can lead to persistent or recurring health problems over time. disease such as allergies or an autoimmune disorder. Early diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. and treatment can help prevent more serious complications such as the spread of the infectionAn infection is the colonization and multiplication of pathogens such as bacteria, viruses, fungi, or parasites in an organism, which often, but not always, leads to a disease. to the inner ear or permanent hearing damage.

Symptom recognition for animal owners and veterinary diagnostic procedures

The recognition of otitis externa by the pet owner often begins with the observation of typical symptoms such as redness, swelling and behavioral changes of the dog. An unpleasant odor or an abnormal discharge from the ear are also clear indications.

The veterinarian will usually perform a thorough examination of the ear for diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients., often with the help of an otoscopeAn otoscope is a medical instrument used to examine the external auditory canal and the eardrum. Otoscopy is a standard procedure in veterinary medicine for the diagnosis of ear diseases in dogs and cats., to get a better view of the ear canal. The condition of the eardrum is checked, and it is searched for foreign bodies or other anomalies. A sample of the ear secretion may be taken and examined microscopically to determine whether there is a bacterial or fungal infection.

If allergies or other underlying diseases are suspected, the veterinarian may suggest additional tests, such as blood tests or allergyAn allergy is an overreaction of the immune system to a normally harmless substance, the allergen. The reaction can include symptoms such as skin rash, itching, sneezing, respiratory distress, or in severe cases, anaphylactic shock. tests, to determine the cause of the inflammation and initiate targeted treatment.

What can pet owners do and professional therapy options

As a first measure for relief, the pet owner can try to keep the affected area clean and dry. Gently wiping the outer ear with a soft, damp cloth can help remove excess dirt and discharge. However, it is important not to clean the inside of the ear canal to avoid further irritation or injury.

It is advisable to prevent the dog from scratching excessively or shaking its head, which could worsen the inflammation. A soft neck collar or a special dog neck brace can help limit access to the ears.

As long as no specific treatment has been prescribed by a veterinarian, no home remedies or over-the-counter products should be used without veterinary advice, as they could worsen the symptoms or obscure the cause of the inflammation. Professional veterinary treatment is crucial to determine and apply the correct therapyTherapy refers to the treatment of diseases or disorders with the aim of alleviating symptoms, promoting healing, or improving quality of life. Therapies can be medicinal, surgical, or through other medical interventions., such as antibiotics, antifungals, or antiallergic drugs.

Outlook on current research

Current research is intensively investigating the role of genetic factors in the susceptibility to inflammation of the external auditory canal in dogs. Different breeds show different predispositions to ear infections, which may indicate genetic differences. Studies are currently analyzing genome data to identify specific genetic markers that are associated with an increased susceptibility to inflammations.

Another focus of research is the identification of new and more effective treatment methods for inflammation of the external auditory canal. While traditional treatments often involve the use of antibiotics and anti-inflammatory drugsAnti-inflammatory drugs are medications that reduce inflammation. They can be divided into nonsteroidal anti-inflammatory drugs (NSAIDs) and corticosteroids and are used in dogs and cats to reduce Inflammatory conditions and Pain., alternative approaches such as probiotics and botanical preparations are being investigated. These could help to stabilize the natural microflora in the ear and reduce inflammatory conditions.

In addition, the role of nutrition in the development and treatment of ear infections is being investigated. Some studies suggest that a special diet rich in omega-3 fatty acids and antioxidants can reduce inflammatory processes in the body. Research projects are evaluating whether such dietary adjustments can reduce the frequency and severity of ear infections in dogs.

The role of environmental factors is also being intensively researched. Scientists are investigating how environmental allergens, humidity, and temperature influence the development of inflammations in the external auditory canal. The goal is to develop preventive measures that reduce the risk of ear infections by minimizing exposureExposure refers to the Contact with or subjection to certain substances, environmental factors, or pathogens. In veterinary medicine, this can include Contact with toxins, allergens, or infectious agents that can cause health problems in dogs and cats. to potential triggers.

A promising area of research is the use of imaging techniques to detect and monitor inflammations early on. Advances in high-frequency ultrasoundUltrasound refers to sound waves that are above the hearing threshold of the human ear. In medicine, ultrasound is used for diagnostic imaging procedures to visualize internal organs, tissues, and blood flow. technology enable detailed images of the ear canal, which can help to identify subtle changes in tissue structure before clinical symptoms occur.

Research into immunological aspects of ear infections in dogs is also being intensified. Scientists are investigating how the dog’s immune systemThe immune system is the body's defense system against infectious agents such as bacteria, viruses, fungi, and parasites. It comprises a complex network of organs, cells, and molecules that work together to protect the body. responds to various pathogens and which mechanisms are responsible for the inflammatory response. The goal is to develop therapeutic strategies that specifically target these immunological processes.

Another innovative approach in research is the development of vaccines against common pathogens of ear infections. These vaccines could significantly reduce the risk of infections and associated inflammations. Experimental studies with prototype vaccines show promising results, but further investigations are necessary to confirm their safety and effectiveness.

The exploration of microbial communities in the ear canal, also known as the microbiome, is also a growing area of research. Scientists are trying to understand how the balance between different microorganisms in the ear affects the health of the ear canal and how dysbiosis contributes to the development of inflammations.

Finally, there are advances in the development of personalized treatment approaches. Based on genetic, microbial, and immunological profiles, future therapies could be individually tailored to the respective dog in order to maximize treatment efficiency and minimize the risk of side effects.

Overall, current research shows a promising future for understanding and treating inflammation of the external auditory canal in dogs. By integrating genetic, microbial, immunological, and environmental findings, more comprehensive and effective treatment strategies can be developed that significantly improve the well-being of dogs.

Frequently asked questions

What are the most common signs of inflammation of the external auditory canal in dogs? The most common signs include redness, swelling, excessive scratching the ear, head shaking, unpleasant odor from the ear, and possibly the leakage of secretions.
Can an ear infectionAn infection is the colonization and multiplication of pathogens such as bacteria, viruses, fungi, or parasites in an organism, which often, but not always, leads to a disease. in dogs heal on its own? In some mild cases, an ear infectionAn infection is the colonization and multiplication of pathogens such as bacteria, viruses, fungi, or parasites in an organism, which often, but not always, leads to a disease. may subside without treatment. However, it is important to identify and treat the cause of the inflammation to avoid chronicChronic refers to a condition or disease that is long-lasting or permanent. Chronic diseases often develop slowly and can lead to persistent or recurring health problems over time. problems and complications.
How is inflammation of the external auditory canal diagnosed? The diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. is usually made by a clinical examination of the ear, in which the veterinarian examines the inner ear for signs of inflammation, infectionAn infection is the colonization and multiplication of pathogens such as bacteria, viruses, fungi, or parasites in an organism, which often, but not always, leads to a disease., or foreign bodies. Additional tests may include smears, cultures, or imaging procedures.
What treatment options are available for an ear infectionAn infection is the colonization and multiplication of pathogens such as bacteria, viruses, fungi, or parasites in an organism, which often, but not always, leads to a disease. in dogs? Treatment may include topicalTopical refers to the direct application of medications or treatments to the skin or mucous membranes for a local effect, without being absorbed into the body. and oralOral means "through the mouth" and refers to the intake of food, medication, or other substances through the mouth. In veterinary medicine, many treatments are administered orally. antibiotics, anti-inflammatory medications, and ear cleaners. In some cases, a dietary adjustment or the avoidance of allergens may also be necessary.
How can I prevent an ear infectionAn infection is the colonization and multiplication of pathogens such as bacteria, viruses, fungi, or parasites in an organism, which often, but not always, leads to a disease. in my dog? Regular cleaning of the ears, avoiding moisture in the ear, a balanced diet, and minimizing exposureExposure refers to the Contact with or subjection to certain substances, environmental factors, or pathogens. In veterinary medicine, this can include Contact with toxins, allergens, or infectious agents that can cause health problems in dogs and cats. to known allergens can help reduce the risk of ear infections.
Can my dog lose his hearing due to an ear infectionAn infection is the colonization and multiplication of pathogens such as bacteria, viruses, fungi, or parasites in an organism, which often, but not always, leads to a disease.? Yes, untreated chronicChronic refers to a condition or disease that is long-lasting or permanent. Chronic diseases often develop slowly and can lead to persistent or recurring health problems over time. inflammations can lead to permanent damage in the ear canal and possibly to hearing loss. It is important to seek veterinary treatment early.
How long does it take for an ear infectionAn infection is the colonization and multiplication of pathogens such as bacteria, viruses, fungi, or parasites in an organism, which often, but not always, leads to a disease. to heal in dogs? The healing time depends on the severity of the inflammation and the chosen treatment. An acuteAcute refers to a condition that occurs suddenly and is usually of short duration. In a medical context, it describes symptoms or illnesses that can quickly become serious and require immediate attention. inflammation can subside within one to two weeks, while chronicChronic refers to a condition or disease that is long-lasting or permanent. Chronic diseases often develop slowly and can lead to persistent or recurring health problems over time. cases may take longer.
Can an ear infectionAn infection is the colonization and multiplication of pathogens such as bacteria, viruses, fungi, or parasites in an organism, which often, but not always, leads to a disease. in dogs be transmitted to humans? In general, ear infections in dogs are not transmissible to humans. However, they can be caused by bacteriaBacteria are microscopic, single-celled organisms that exist in almost every environment on Earth. Some types of bacteria are beneficial or even essential to life, while others can cause disease. or yeasts that can also cause infections in humans if the skin barrier is damaged.
What role does breed play in susceptibility to ear infections? Certain breeds, especially those with long, drooping ears, such as Cocker Spaniels and Basset Hounds, are more prone to ear infections due to the limited air circulation and the tendency for moisture to accumulate in the ear canal.
When should I take my dog to the vet if I suspect an ear infectionAn infection is the colonization and multiplication of pathogens such as bacteria, viruses, fungi, or parasites in an organism, which often, but not always, leads to a disease.? If you notice signs such as redness, swelling, scratching the ear, unpleasant odor, or discharge, you should see a veterinarian as soon as possible for appropriate diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. and treatment.