Otodectes cynotis: A comprehensive review of the ear mite

What is Otodectes cynotis?

Otodectes cynotis is a mite in the family Psoroptidae that is commonly found in domestic animals, especially cats and dogs. It is also known as ear mite and causes a specific form of mange in affected animals, known as ear mange. This type of mite is widespread worldwide and affects both domestic and wild animals.

Ear mite morphology and life cycle

The ear mite is a tiny parasite that can hardly be seen with the naked eye. Female mites reach a size of 350 to 500 µm, while males are slightly smaller. The body of the mite is elongated and oval in shape and has strong legs. These legs end in short adhesive stalks that allow the mite to cling to its host's skin.

Otodectes cynotis
Otodectes cynotis 2

Stages of development

The life cycle of Otodectes cynotis occurs in several stages:

  • Egg : The eggs are oval and around 170 to 200 µm in size. The females deposit them on the skin in the external ear canal.
  • Larvae : After a few days, the eggs hatch into larvae that feed on skin cells and exudate.
  • Nymphal stages : The larvae develop into the adult mite through two nymphal stages.
  • Adult mite : The adult mites live for about two months and continue the infestation.

The entire development cycle takes approximately three weeks.

Host range and transmission

The ear mite is not host specific, meaning it can affect different animal species. The most common hosts include:

  • Cats
  • dogs
  • Ferret
  • Foxes
  • Wild animals such as lynxes and martens

Mites are usually transmitted through direct contact between animals, especially in close physical contact, such as between mother animals and their young. Infection from animal to animal is therefore easily possible, especially in households with several pets.

Otodectes cynotis can only survive outside the host under certain conditions. High humidity (>80%) and mild temperatures favor the mites' survival in the host's environment for several months. However, in dry environments the mites die quickly.

Thanks go to our colleague Joanna Kulik for these recordings

Symptoms and clinical picture

The symptoms of an infestation with Otodectes cynotis can vary depending on the host and the severity of the infestation.

Symptoms in cats

Infestation with Otodectes cynotis in cats is manifested by a variety of symptoms, which can vary in severity from animal to animal. It is often the case that cats hardly show any symptoms despite a massive accumulation of excretions in the ear canal. Others experience severe itching, even if the amount of discharge is small.

Typical signs of mite infestation in cats include:

  • Dark, crumbly deposits in the ear : These deposits have a waxy, often “coffee grounds-like” consistency and a characteristic, unpleasant odor. They consist of a mixture of cerumen (earwax), dead skin cells, blood and exudate. This buildup can block the ear canal and lead to further complications.
  • Itching and head shaking : Cats often scratch their ear and shake their head to get rid of the irritation. This itching occurs due to the movement of the mites and the resulting allergic reaction of the skin to the mite antigens.
  • Ear pain and sensitivity : Touching the ears can be painful for the cat. The skin around the ears may look red, irritated, and inflamed. In severe cases, this can also lead to injury from excessive scratching.
  • Otitis externa : As a result of the mite infestation, an external ear infection (otitis externa) can occur. This causes swelling and redness of the ear canal, the cat becomes sensitive to touch, and the itching may become more intense. If left untreated, the inflammation can worsen and risk spreading to the middle or inner ear.
  • Behavioral changes : Cats with ear mites tend to become withdrawn, irritable and restless. In some cases, there may be a general malaise caused by the constant irritation of the ears.

Symptoms in dogs

Dogs have different symptoms than cats, especially the often very pronounced itching. Dogs are generally more sensitive to Otodectes cynotis infestation, resulting in more obvious clinical signs:

  • Violent itching : The itching in dogs is usually so severe that they scratch their ears intensely and shake their heads frequently. This can lead to self-harm as dogs often scratch sensitive skin with their claws. In some cases, the dog may rub the affected ear on the ground to relieve the itching.
  • Few secretions in the ear canal : In contrast to cats, dogs show less accumulation of cerumen or exudate. Nevertheless, the ear canal is often inflamed and red. The lack of “coffee grounds-like” earwax can make the infestation less obvious, which can delay diagnosis.
  • Otitis externa : The ear infection in dogs is usually more severe than in cats. The ears are often hot, swollen, and painful, especially when touched. In severe cases, otitis externa may be associated with a bacterial or yeast infection, which increases symptoms.
  • Othematoma : Constant shaking of the head and scratching can cause bruising in the ear (othematoma). This causes blood to collect between the skin and cartilage of the ear, causing painful swelling. If left untreated, this can lead to permanent deformation of the ear.
  • Weeping and sore eczema : In the case of intensive self-traumatization, the skin of the ear can become severely irritated and develop weeping eczema. These open sores increase the risk of secondary infections, which further worsen the itching and inflammation.
  • Behavioral changes : Due to the constant irritation and itching, dogs often show behavioral changes such as restlessness, irritability or aggressiveness. Some dogs withdraw because they feel uncomfortable and the ear pain is very distressing.

Symptoms in dogs and cats can vary greatly depending on the severity of the infestation. Early diagnosis and treatment are therefore crucial to alleviate animal suffering and avoid serious complications.

Diagnosis of ear mites

Diagnosis is usually made by direct examination of the ear canal and auricle. The mites can often be identified directly using an otoscope. Another method is to remove the cerumen (earwax) with a cotton swab and examine it under a microscope. Alternatively, the removed cerumen can be placed in a container of water, whereupon the mites will migrate within an hour at room temperature and become visible on the surface.

Diagram of the life cycle of Otodectes cynotis

graph LR; egg --> larva; Larva --> Nymph1; Nymph1 --> Nymph2; nymph2 --> adults; adults --> egg;

Possible secondary diseases in dogs and cats after a mite infestation

If not recognized and treated in a timely manner, an infestation with Otodectes cynotis These secondary problems usually arise from the persistent irritation, inflammation and injury caused by the mites and the animal's subsequent reaction.

1. Otitis externa (inflammation of the external ear canal)

One of the most common complications in dogs and cats is otitis externa , an inflammation of the external ear canal. This can be triggered by the mites themselves or by the excessive production of earwax and inflammatory secretions. Often, otitis externa is secondarily infected by bacteria or yeast, which can make the inflammation even worse.

Symptoms of otitis externa include:

  • Severe redness and swelling of the ear canal
  • Painful touching of ears
  • Constant head shaking and scratching
  • Unpleasant smell from the ear
  • Yellowish or brown, sometimes purulent, discharge

If left untreated, otitis externa can become chronic and cause permanent damage to the ear.

2. Otitis media and otitis interna (inflammation of the middle and inner ear)

If external otitis is not treated in time, the inflammation can spread to the middle and inner ear. This can have more serious consequences because the middle ear and inner ear contain more delicate structures that are important for the animal's hearing and balance.

Possible symptoms of otitis media/internal:

  • Severe dizziness (shaky gait, head tilt)
  • Hearing loss
  • Severe pain in the ear
  • Loss of appetite and general malaise

Inflammation of the inner ear can cause permanent balance problems and, in severe cases, even complete hearing loss in dogs and cats.

3. Othematomas (bruises in the ear)

In dogs and cats, severe itching often leads to violent scratching and head shaking. This constant mechanical irritation can lead to an othematoma - a bruise in which blood gets between the skin and the cartilage of the ear. This leads to painful swelling of the ear.

An othematoma can be recognized by:

  • Sudden, painful swelling of the auricle
  • Warm, soft thickening of the ear

Othematomas often require surgical treatment to remove the accumulated blood and prevent permanent deformation of the ear.

4. Secondary skin infections (pyoderma)

Constant scratching and biting of the affected areas can lead to open wounds and irritated areas of skin. These wounds represent a gateway for bacterial infections that can easily spread to the damaged skin. One of the most common secondary diseases is pyoderma , a purulent skin infection.

Signs of a secondary infection include:

  • Redness and swelling of the skin
  • Pustules or weeping sores
  • Bad smell due to bacterial infestation
  • Severe pain and worsening of itching

An untreated skin infection can spread to deeper layers of the skin and lead to more serious systemic infections.

5. Behavioral disorders and stress

In addition to the physical consequences, a persistent ear mite infestation can also lead behavioral problems and stress The constant itching and pain in the ear puts a lot of strain on the animal. As a result, dogs and cats often react with:

  • Irritability and aggressiveness
  • withdrawal and apathy
  • Restlessness and nervousness

In some cases, the stress can cause the animal's general health to deteriorate, weakening the immune system and increasing susceptibility to other illnesses.

6. Hearing loss

Chronic infestation and the resulting inflammation can lead to long-term hearing loss . This is especially the case if the inflammation penetrates deep into the middle ear or inner ear. The damage to the delicate structures of the ear is often irreversible, especially in advanced cases.

7. Secondary ear mite infection in humans

Although rare, ear mites can also temporarily affect humans. papular dermatitis or mild otitis externa may occur. However, infestation in humans is usually only temporary and does not lead to long-term health problems.


Through early diagnosis and treatment of ear mites, these secondary diseases can be avoided in most cases. Regular ear checks, especially for cats and dogs with sensitive ears, are an important measure to prevent ear mites and the resulting complications.

General treatment of Otodectes cynotis

Treatment for ear mite infestation in dogs and cats usually begins with a thorough cleaning of the affected ear to remove the mites and their residue. A mild antiseptic is often used to clear the ear canal of cerumen, exudate and mite deposits. This step is crucial to promote the healing process and improve the effect of subsequent drug therapy.

The actual antiparasitic treatment usually takes place with so-called spot-on preparations or ear drops, which contain specific active ingredients to kill the mites. Commonly used active ingredients are:

  • Moxidectin (often in combination with imidacloprid )
  • Selamectin
  • Ivermectin

These preparations work by attacking the nervous system of the mites and thus killing them. It is important to repeat the treatment every 4 weeks until mites are no longer detectable to ensure complete treatment success.

Treatment of specific secondary diseases

In addition to combating the ear mites themselves, it is often necessary to specifically treat the secondary diseases that arise from the mite infestation.

1. Treatment of otitis externa

Otitis externa , i.e. inflammation of the external ear canal, often requires the use of anti-inflammatory medications . These may be given in the form of ear drops containing corticosteroids to relieve the swelling and irritation. In cases where there is a secondary infection caused by bacteria or yeast, antibiotic or antifungal ear drops used to combat the infection.

  • Corticosteroids : Reduce inflammation and relieve itching.
  • Antibiotics/Antifungals : Fight secondary infections caused by bacteria or yeast.

2. Treatment of otitis media and otitis interna

If the inflammation has already spread to the middle or inner ear, more intensive treatment required. In these cases, systemic therapy is necessary, i.e. the administration of antibiotic medication in tablet or injection form. These medications are usually given over a long period of time to completely eliminate the inflammation and prevent it from spreading to surrounding tissues.

In severe cases, it may also be necessary to treat the ear surgically to drain the pus or inflammatory material to relieve pressure in the ear.

3. Treatment of othematomas

An othematoma usually requires surgical treatment. The vet will drain the accumulated blood by making a small incision in the affected ear. To prevent the hematoma from forming again, a drain may be placed or the ear may be sutured. In some cases, padding is also applied to the ear to stabilize the bruise.

After surgery, it is important to control itching to prevent re-injury from scratching. Anti-inflammatory medications and painkillers are often given for this purpose.

4. Treating skin infections (pyoderma)

pyoderma caused by scratching, the vet will often antibiotic ointments or tablets to combat the bacterial infection. In addition, special skin care with antiseptic shampoos be recommended to clean the affected skin areas and support wound healing.

In severe cases, systemic treatment with antibiotics over several weeks may be necessary to completely clear the infection.

5. Stress and behavior management

In addition to physical treatment, it may be important to support the animal's overall well-being. For severe stress and behavioral changes caused by the ear mites, calming supplements or pheromone-based products help calm the animals and promote healing. It can also make sense to make the animal's habitat less stressful by creating retreats and rest areas.

6. Hearing loss: long-term management

If the infestation causes permanent hearing loss , this is usually irreversible. The management of hearing-impaired animals requires adjustments to everyday life to maintain quality of life. This includes:

  • Adaptation of communication : Using visual signals to guide the animal.
  • Safety measures : Since hearing-impaired animals are less able to perceive dangers, precautionary measures should be taken, such as keeping the animal on a leash to protect it from unforeseeable dangers.

Early and comprehensive treatment of Otodectes cynotis and possible complications is the key to preserving the health and well-being of affected animals. It is crucial to follow the treatment plan carefully and have regular check-ups with the vet to ensure that the ear mites have been completely eliminated and any complications have been successfully treated.

Frequently asked questions about Otodectes cynotis

How do I recognize an Otodectes cynotis infestation in my pet?

An infestation with the ear mite Otodectes cynotis can manifest itself in various symptoms in dogs and cats. One of the most noticeable signs is severe itching around the ears. Your pet may shake his head frequently and scratch his ears intensely. In cats in particular, you can often find a dark, crumbly mass in the ear canal that has a consistency similar to coffee grounds and smells unpleasant. These deposits consist of earwax, dead skin cells and blood and are typical of an ear mite infestation.
Additionally, your pet's ears may sensitive external ear infection (otitis externa) , characterized by redness and swelling of the ear canal, may Dogs often show less visible deposits, but a particularly pronounced itch , which can lead to self-harm, for example through excessive scratching, which tears the skin.
It is important to recognize symptoms early as an untreated infestation can lead to serious complications such as ear infections, hearing loss or secondary infections. If you suspect that your pet is affected by ear mites, you should see a veterinarian as soon as possible for diagnosis and treatment.

How is an infestation with Otodectes cynotis diagnosed?

The diagnosis of an infestation with Otodectes cynotis is usually made by a veterinarian. The first indication of the infestation can be the typical symptoms, such as itching and brown-black deposits in the ear. For further evaluation, the veterinarian will use an otoscope to examine the ear canal more closely. With this device, the mites can often be made directly visible in the external auditory canal or in the auricle.
Another diagnostic method is to use a cotton swab to remove cerumen (earwax) from the ear canal and examine it under a microscope. The mites or their eggs are easily recognized. An alternative, very simple technique is to put the extracted material in a glass of water. The mites contained in the cerumen migrate within an hour at room temperature and can swim on the surface of the water, allowing visual confirmation of the infestation.
It is important that the veterinarian also rule out other possible causes of ear problems, such as bacterial infections, yeast, or allergies, to determine the correct course of treatment.

What treatment options are there for an infestation with Otodectes cynotis?

Treating an ear mite infestation always begins with a thorough ear cleaning to remove excess cerumen and mite deposits. This allows subsequent drug therapy to work better. Antiseptic ear cleaners are often used to disinfect the ear canal and remove exudates.
The actual antiparasitic treatment then takes place. There are various spot-on preparations and ear drops that are specifically effective against Otodectes cynotis. Common active ingredients include:
Moxidectin (often in combination with imidacloprid )
Selamectin
Ivermectin
These medications kill the mites by attacking the parasites' nervous system. The treatment must be repeated every 4 weeks until mites are no longer detectable. It is also important to treat other animals in the household, even if they are not showing symptoms, to prevent reinfection.
In some cases, particularly in cases of severe inflammation or secondary infection, the veterinarian may also anti-inflammatory and antibiotic ear drops to help heal the inflamed ear canal. Regular check-ups with the vet are essential during the treatment period in order to monitor the success of the treatment.

What complications can occur if an ear mite infestation is left untreated?

An untreated infestation with Otodectes cynotis can lead to a number of serious secondary diseases in dogs and cats. The constant irritation of the ear canal by the mites often causes otitis externa (inflammation of the external ear canal). This inflammation can spread further into the middle and inner ear and lead to otitis media or otitis interna . In these cases, the animal can not only suffer from severe pain, but also suffer permanent damage, such as hearing loss or balance problems , as the inner ear is responsible for balance.
In addition, affected animals tend to scratch their ears vigorously or shake their heads, which can lead
othematomas These are painful bruises in the auricle that require surgical treatment. Another problem is secondary infections caused by scratching and open skin. Bacteria and yeast can easily colonize the inflamed areas, which can lead to purulent skin infections (pyoderma). These infections worsen the animal's condition and significantly prolong the healing process.

How can I prevent another infestation with Otodectes cynotis?

Preventing new ear mite infestations in dogs and cats requires ear checks It is important to keep the ears clean and dry, especially for animals that have already been affected by Otodectes cynotis. be checked
regularly for any unusual buildup An important preventative measure is the use of spot-on preparations , which are applied regularly to prevent re-infestation with ear mites and other parasites. These preparations often provide long-term protection and should be used monthly or as directed by the veterinarian.
In households with multiple animals, care should be taken to treat all animals at the same time, even if not all of them show symptoms. Ear mites are highly contagious, and treating just one animal can lead to constant reinfection. sleeping places and the surrounding area should be cleaned and disinfected regularly, as the mites can also survive outside the host under favorable conditions.
Through early treatment and preventative measures , you can ensure that your pet is protected from re-infestation and remains healthy in the long term.

Summary Otodectes cynotis

Otodectes cynotis is a global ear mite that primarily affects pets such as cats and dogs. Otodectes cynotis belongs to the family Psoroptidae and is known to cause a specific form of mange called ear mange. Otodectes cynotis lives in the external auditory canal of affected animals, where it feeds on skin cells and exudates. The life cycle of Otodectes cynotis includes several developmental stages, from egg to adult mite, with this cycle lasting approximately three weeks.

Transmission of Otodectes cynotis occurs through direct contact between infected and uninfected animals. Young animals are particularly susceptible, as Otodectes cynotis is often passed from mother to young animal through close physical contact. A typical symptom of an infestation with Otodectes cynotis is severe itching, which is often accompanied by a characteristic “coffee grounds-like” earwax.

In cats, infestation with Otodectes cynotis to a dark, waxy mass in the ear canal that smells strongly, while in dogs the main cause is severe itching. Otodectes cynotis can lead to serious complications, such as otitis externa or even othematomas caused by intensive scratching. In addition, Otodectes cynotis cause secondary infections that further damage the skin and ears.

The diagnosis of Otodectes cynotis is usually made by examining the ear canal using an otoscope or by microscopic analysis of the earwax, in which the mites can be directly visualized. Treatment for Otodectes cynotis involves thorough cleaning of the ear canal as well as the application of antiparasitic spot-on preparations that kill the mites. To prevent reinfection by Otodectes cynotis , treatment should be repeated over several weeks and all animals in the household should be treated.

Although Otodectes cynotis primarily affects domestic animals, in rare cases it can also cause temporary infestation in humans, resulting in papular dermatitis or mild otitis externa. Due to the ease of transmission between animals and the potential severity of complications, Otodectes cynotis

Infestation with Otodectes cynotis be prevented through regular checks and preventive measures, such as the use of antiparasitic agents. The importance of early treatment and prevention cannot be underestimated, as Otodectes cynotis can cause significant health problems in pets if left untreated.

Prevention of Otodectes cynotis requires not only treatment of infected animals but also careful hygiene of the environment. Otodectes cynotis can survive outside the host in a moist environment for several months. Therefore, pet sleeping places and living spaces should be cleaned and disinfected regularly to shorten Otodectes cynotis This helps prevent reinfection and minimize Otodectes cynotis

If there is a confirmed infestation of Otodectes cynotis , it is critical that all pets in the household be treated at the same time, even if not all are showing symptoms. Because Otodectes cynotis is easily transmitted from animal to animal, one untreated animal can spread the infection back to the others, leading to a cycle of constant reinfection.

In addition to treating the Otodectes cynotis infection directly, it is important to treat possible secondary infections that may arise from scratching or ear infections. For otitis externa caused by Otodectes cynotis , the veterinarian will often prescribe anti-inflammatory and antibiotic ear drops to control the inflammation and combat bacteria or yeast that may colonize the irritated tissue.

Long-term protection against Otodectes cynotis can be ensured through the regular use of spot-on preparations or antiparasitic collars, which are effective not only against mites but also against other parasites such as fleas and ticks. These products are particularly useful in households with multiple pets or in environments with a high risk of infection as they provide a preventive protective barrier.

In addition to medical treatment, cats and dogs' ears should be checked regularly. detect early signs of re-infestation with Otodectes cynotis At the first symptoms, such as increased shaking of the head, itching or deposits in the ear, action should be taken immediately.

In summary, Otodectes cynotis is a widespread ear mite that requires targeted measures to treat and prevent. Through a combination of regular ear care, antiparasitic treatment and hygienic measures, an infestation with Otodectes cynotis successfully combated and a recurrence prevented. The timely detection and treatment of these parasites ensures that the well-being of dogs and cats is maintained in the long term and that serious secondary diseases are avoided.

further information: https://www.cliniciansbrief.com/column/category/column/capsules/mighty-early-ear-mite-elimination

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