When to see a vet urgently
Contact a vet promptly if ear symptoms are accompanied by the following:
- The ear is so painful that your cat will not allow examination or stops eating.
- The ear flap suddenly develops a thick, soft swelling.
- Blood or pus comes from the ear and your cat's general condition deteriorates.
- The head tilts abnormally or balance and movement become difficult.
You can find a vet near you. Balance problems must not be interpreted as ordinary itchy ears.
Overview
Otodectes cynotis spreads easily through direct contact between animals. The mites irritate the skin of the ear canal, causing inflammation and characteristic dark crusts. Without treatment, infestation can be complicated by bacterial or fungal infections and develop into chronic otitis.
The mite lives on the skin surface and does not burrow into ear canal tissue. Its life cycle includes eggs, larvae, immature stages and adult mites. The life cycle usually takes place on the animal. The way treatment is given and completed is therefore selected according to the properties of the product used.
Ear mites can also occur outside the ears, for example on the skin of the head or neck. Skin symptoms may then extend beyond the ear canal. Simply removing visible ear discharge therefore does not, by itself, mean the infestation has been eliminated.
Causes
The underlying cause is infestation with ear mites. Routes of transmission include:
- direct contact with affected animals, such as cats, dogs and ferrets
- through bedding and grooming equipment, such as brushes
- from a mother to her kittens during care and feeding
Close contact with an infested animal is a key route of transmission. A dog or another cat in the same household may need to be included in the treatment plan even without itching that you can notice. Tell your vet about any ferrets and other close animal contacts too, so that appropriate assessment and treatment can be chosen for each species.
Survival in the environment has been described, but direct animal contact is central to controlling spread. Handle used bedding and grooming equipment according to the clinic's instructions. Cleaning the home alone does not replace treating the animals.
Risk factors
Cats particularly susceptible to ear mites include:
- kittens and young cats
- animals from shelters or breeding catteries
- cats with weakened immune systems
- animals with outdoor access
There is limited cat-specific information on the importance of individual risk factors. In particular, immune deficiency cannot be inferred from ear mites alone, as an otherwise healthy cat can also become infested. The finding is common in young cats, but symptoms in an adult cat are not ruled out on age grounds either.
Main symptoms
Ear mite infestation appears as:
- intense itching and scratching of the ears
- head shaking
- redness and inflammation of the ear canal
- dark, dry discharge resembling coffee grounds
- an unpleasant smell from the ears
- crusts and sores around the ears
- restlessness and reduced appetite
Dark discharge resembling coffee grounds is a typical finding, but does not confirm the diagnosis on its own. Other ear diseases can produce similar discharge. Symptoms may affect one or both ears, and their severity varies considerably.
The number of mites does not always match the severity of outward symptoms. There may be abundant discharge and a strong reaction even when only a few mites are found. Another cat may have many mites without obvious itching. Calm behaviour or a second ear that looks clean therefore does not guarantee freedom from infestation.
Complications and consequences
Without treatment, ear mite infestation can lead to:
- chronic otitis
- secondary bacterial and fungal infections
- a ruptured eardrum
- an ear flap haematoma from persistent scratching
- hearing impairment
An ear flap haematoma develops when blood accumulates between the skin and cartilage of the ear flap. Vigorous shaking and scratching can rupture small blood vessels. The ear flap then feels thick and soft. This is a different problem from discharge inside the ear canal.
A haematoma can be painful and, untreated, leave a permanent ear flap deformity. Your vet assesses the need for drainage, surgery or another treatment. The cause of itching is investigated at the same time, as treating the blood collection alone does not remove the ear canal problem. A haematoma also does not prove ear mites: another irritating ear condition may be responsible.
As well as removing blood, treatment of a haematoma may require closure of the space between skin and cartilage, with stitches for example, to prevent blood from accumulating again. Sometimes a drain, a tube that removes fluid, and support for the ear flap are needed. The method and aftercare are selected according to the size and location of the blood collection and your cat's situation.
Diagnosis at the vet
The following are used to confirm diagnosis:
- otoscopy, an examination of the ear canal
- microscopic examination of discharge to detect mites and eggs
- exclusion of other causes of otitis
An otoscope is used to examine the ear canal and look for moving mites and signs of inflammation. If the ear is very tender or full of discharge, proper examination and handling may require sedation. Assessing the eardrum affects which cleaning methods and topical medicines can be used safely.
A microscopic sample can be checked for mites and their developmental stages. Other samples may be needed to assess bacteria or yeast. Sampling is your vet's task: do not put a cotton bud deep into the ear at home to look for mites.
If mites are not seen immediately, interpretation also takes account of the amount of discharge, inflammation and the rest of the clinical picture. Demonstrating mites can be difficult, particularly in an ear containing a lot of pus. Persistent symptoms or a poor treatment response also prompt investigation of other causes of otitis.
Treatment and animals in contact
Your vet selects a medicine effective against ear mites according to your cat's age, condition, inflammation and any mites elsewhere on the skin. Some treatments are given into the ear; others act after application elsewhere on the skin or through another systemic route. The route alone does not indicate effectiveness: not every external parasite product is intended for this infestation.
Treatment of dogs and cats in the same home is planned together. Each animal receives a product suitable for its species and situation. Improvement in one animal's symptoms does not prevent re-exposure if another contact animal remains a source of infestation. Tell your vet about all parasite medicines already used so overlapping treatments can be considered.
A secondary bacterial or yeast infection may need separate medication. Eliminating the parasite and treating the inflamed ear complement one another. The plan may also include cleaning, but cleaning a very painful ear may need to be delayed or performed under sedation.
Ear care at home
Ask your vet to demonstrate suitable cleaning and medicine administration. Use only the recommended cleanser. Products containing alcohol or hydrogen peroxide can irritate an inflamed ear canal. Ear pain, redness or a suspected damaged eardrum are reasons to ask for instructions before cleaning.
Visible, loosened discharge can be removed as instructed with soft cotton wool or a gauze pad. A cotton bud can push discharge deeper or damage the ear canal and eardrum. Do not try to scrape off material that is stuck. If cleaning clearly hurts, stop and contact the clinic.
Excessive cleaning can also irritate the skin. Not every cat's healthy ears need routine washing. For an ear under treatment, agree separately on the need for cleaning, the suitable product and how cleaning relates to topical medication, as some cleansers can reduce a medicine's effects.
Assessing treatment results
Monitor changes in scratching, shaking, smell and discharge. Your vet may recommend a follow-up to confirm that mites have gone and any inflammation has resolved. Do not stop treatment yourself simply because discharge has decreased. Continuing symptoms may be due to remaining infestation, new exposure or another concurrent ear disease, for example.
Prevention
To reduce the risk of ear mites, the following are recommended:
- regular external parasite treatment, such as spot-on products applied to the neck or sprays
- controlled contact with animals that go outdoors
- treatment of all household animals when ear mites occur
- regular veterinary checks of the ears
A parasite product's suitability for preventing ear mites is checked separately: target species and indications vary between products. The aim is to treat exposed contact animals, rather than use the same product indiscriminately on every animal in the home. Investigate ear symptoms in new animals before close contact with other pets.
What it means for owners
Ear mite infestation is very common and easily treated at an early stage. Remember that head shaking, ear scratching or dark ear discharge are reasons to seek veterinary care immediately. Prompt treatment eliminates the parasite and prevents complications.
Frequently asked questions
Does dark ear discharge always mean ear mites?
No. Discharge resembling coffee grounds is consistent with infestation, but other causes exist. Diagnosis is confirmed by examining the ear and, where necessary, looking at discharge under a microscope.
Does another cat or dog without symptoms need treatment?
Contacts of an infested animal are included in the same treatment plan, even without visible symptoms. Your vet selects suitable treatment for each to prevent infestation passing between animals.
Can I clean the ear with a cotton bud?
Do not insert a cotton bud into the ear canal. It can damage tissue or push discharge deeper. Your vet advises on cleaning, and a painful ear is examined before handling at home.
Why can ear symptoms continue after mite treatment?
A secondary infection, new exposure or another ear disease can maintain symptoms. Follow-up assesses both elimination of the parasite and the condition of the ear canal, rather than automatically repeating the same treatment.
This article is for general information only and is not a guide to treatment. If you notice the first signs of illness, contact your vet.
Paw4care editorial team
Sources
- Otodectic Mite, Companion Animal Parasite Council, accessed 2026-11-03.
- Ear Mites: Tiny Critters that can Pose a Major Threat, Cornell Feline Health Centre, accessed 2026-11-03.
- Ear Mites in Cats and Dogs, VCA Animal Hospitals, accessed 2026-11-03.
- Ear Cleaning and Administering Ear Medication in Cats, VCA Animal Hospitals, accessed 2026-11-03.
- Haematoma of the Ear in Cats, VCA Animal Hospitals, accessed 2026-11-03.
- Bekämpfung von Ektoparasiten bei Hunden und Katzen, ESCCAP-Empfehlung Nr. 3, ESCCAP Deutschland, accessed 2026-11-03.
