Ear Mites in Pets: Detection, Treatment, and Prevention

Ear mites (Otodectes cynotis) are tiny, spider-like parasites that live in the ear canals of dogs, cats, rabbits, and ferrets. They're barely visible to the naked eye — about 0.3–0.4mm — and they feed on ear wax, oils, and skin debris. Their entire 3-week life cycle takes place inside the ear, from egg to adult.

"Ear mites are one of the most satisfying conditions to treat because the cure is so straightforward. A single dose of a modern antiparasitic and the problem is solved. The key is making the correct diagnosis — many owners assume any ear problem is mites, but in adult dogs especially, it's much more likely to be allergies." — Dr. Sarah Chen, DVM

Ear mites spread through direct contact between animals. A mother cat passes them to her kittens during nursing. Shelter cats spread them in shared bedding. Dogs pick them up from infected cats. The mites can survive off the host for a short period (days to weeks in the environment), but direct contact is the primary route.

Important prevalence patterns:

• Kittens and young cats — the most commonly affected group; prevalence in shelter kittens can exceed 50%
• Outdoor cats — much higher risk than indoor-only cats due to contact with strays
• Puppies — common, often acquired from the breeder or mother
• Adult dogs — relatively uncommon; if an adult dog has itchy ears, bacterial/yeast infection or allergies are far more likely

Ear mites are species-crossing — cats can infect dogs and vice versa. They do not infect humans, though in rare cases they can cause a temporary, self-limiting rash on people who handle heavily infested animals.

Ear mites produce a very characteristic set of symptoms that, once you've seen them, are hard to mistake for anything else:

The Classic Signs

• Dark, crumbly discharge — the hallmark sign. It looks like coffee grounds or dark chocolate crumbs, and it fills the ear canal. This is a mixture of dried blood, mite waste products, and ear wax
• Intense itching — affected pets scratch their ears vigorously and frequently, often with the hind foot
• Head shaking — persistent, forceful shaking that may lead to ear flap (aural) hematomas
• Ear redness and inflammation — the ear canal and inner ear flap become swollen and irritated
• Odour — a mild, musty smell (distinct from the foul smell of bacterial infection)

Ear Mites vs Other Ear Problems

It's important to differentiate mites from other conditions that look similar:

• Yeast infection — brown, waxy discharge but usually wet and sticky, not dry and crumbly. Often smells sweet/yeasty
• Bacterial infection — yellow, green, or creamy discharge with a foul smell
• Allergic otitis — red, waxy ears that are itchy but may have minimal discharge

The Home Test (Not a Substitute for Vet Diagnosis)

If you collect a sample of the dark discharge on a piece of white paper and look very closely (or use a magnifying glass), you may see tiny white specks moving. These are adult mites. However, a definitive diagnosis requires your vet to examine a sample under a microscope or use an otoscope — the mites are clearly visible as moving white dots against the dark debris.

Always get a vet diagnosis rather than treating presumptively. Treating for mites when the real cause is a bacterial infection wastes time and allows the infection to worsen.

Ear mite treatment has improved dramatically in recent years. Gone are the days of twice-daily ear drops for three weeks — modern treatments are faster, easier, and more reliable:

Systemic (Whole-Body) Treatments — Preferred

• Selamectin (Revolution/Stronghold) — a single topical application to the back of the neck kills ear mites, intestinal worms, and fleas simultaneously. Often curative with one dose, though some vets recommend a second dose after 30 days
• Moxidectin/imidacloprid (Advocate/Advantage Multi) — similar single-dose topical application; highly effective
• Fluralaner (Bravecto) — a single oral or topical dose provides extended protection; increasingly used off-label for ear mites
• Ivermectin — injectable or oral; very effective but not recommended for certain breeds (Collies, Shelties) due to MDR1 gene sensitivity

Topical Ear Treatments

• Acarexx (ivermectin otic) — single in-ear treatment administered by your vet
• Milbemycin ear drops — applied directly into the ear canal; effective but requires cooperation from the pet
• Combination ear products — some products treat mites + secondary bacterial/yeast infection simultaneously

Critical Treatment Rules

• Treat ALL pets in the household — even those without symptoms. Mites spread easily, and untreated pets will reinfect treated ones
• Clean the ears — gently remove debris before or during treatment so medication can reach the mites
• Wash bedding — hot wash all pet bedding, blankets, and soft toys to eliminate environmental mites
• Repeat if needed — the mite life cycle is 3 weeks, so a second treatment at 2–4 weeks ensures any eggs that survived the first treatment are eliminated

For broader parasite prevention strategies, see our complete guide to common parasites in dogs and cats.

Left untreated, ear mites can lead to serious complications that are far harder (and more expensive) to resolve than the mites themselves:

Aural Hematoma

Vigorous head shaking and ear scratching can rupture blood vessels inside the ear flap, causing it to swell with blood — creating a puffy, pillow-like swelling called an aural hematoma. This requires veterinary treatment:

• Surgical drainage — the ear flap is incised, blood is removed, and the flap is sutured to prevent refilling
• Steroid injection — some vets inject corticosteroids into the hematoma after drainage
• Without treatment, the hematoma eventually resolves on its own but leaves a permanently thickened, crumpled 'cauliflower ear'

Secondary Bacterial Infection

Mite-damaged ear canals are vulnerable to bacterial and yeast overgrowth. Signs that a secondary infection has developed on top of the mite infestation include:

• Change from dry, dark discharge to wet, coloured (yellow/green) discharge
• Foul smell (mites alone have a mild odour)
• Increased pain and swelling

Secondary infections require additional treatment with appropriate antibiotics or antifungals alongside mite treatment.

Middle Ear Involvement

In severe, long-standing infestations, mites can penetrate the eardrum and establish in the middle ear. This causes:

• Head tilt and balance problems
• More severe pain
• Potential hearing loss

Middle ear involvement requires extended treatment, often with systemic medication, and carries a longer recovery time.

Prevention is straightforward and highly effective with modern parasite control products:

Year-Round Parasite Prevention

The simplest prevention strategy is using a monthly or quarterly broad-spectrum antiparasitic that covers ear mites. Products that protect against ear mites include:

• Selamectin (Revolution/Stronghold) — monthly topical; covers fleas, mites, roundworms, heartworm
• Moxidectin/imidacloprid (Advocate) — monthly topical; similar broad coverage
• Fluralaner (Bravecto) — every 3 months; primarily for fleas/ticks but effective against mites

If your pet is already on one of these products, ear mite infestation is extremely unlikely.

New Pet Protocols

• Vet check within 48 hours — have any new pet (especially kittens, shelter cats, or puppies) examined before introducing to your household
• Quarantine period — keep new pets separate from resident pets for 2 weeks while parasite treatment takes effect
• Treat before introducing — apply a broad-spectrum antiparasitic to the new pet immediately

Multi-Pet Households

• Keep all pets on regular parasite prevention — one unprotected animal can be a reservoir
• If one pet is diagnosed with ear mites, treat every dog, cat, and ferret in the home simultaneously
• Wash shared bedding in hot water

For a complete overview of parasite prevention including fleas and ticks, heartworm, and intestinal parasites, see our dedicated prevention guides.