Aural discharge

What It Is

A healthy ear produces a small, unnoticeable amount of wax, so discharge becomes a concern once it builds up visibly, changes color, or carries an odor. Dark brown, crumbly discharge often points toward yeast or ear mites, while a yellow or greenish discharge suggests bacterial infection. Dogs with long, floppy ears or hairy ear canals are especially prone to trapped moisture and recurring discharge. Rabbits and some livestock can also develop ear canal infections, and in rabbits this sometimes extends deeper and affects balance.

Common Causes

Ear mites are a frequent cause in kittens and young cats, producing a dark, dry, coffee-ground-like discharge along with intense itching. Bacterial and yeast infections thrive in ears that stay damp after swimming or bathing, or in dogs with allergies that cause chronic ear inflammation. A grass awn or other foreign body lodged in the canal causes sudden, often one-sided discharge and head shaking. Allergies, whether to food or something in the environment, make the ear canal more prone to overgrowth of the yeast and bacteria that normally live there in small numbers.

When It Is an Emergency

Discharge paired with a swollen, painful ear flap that feels like a fluid-filled cushion suggests a hematoma, which benefits from prompt veterinary drainage. An eardrum that may be ruptured, suggested by blood-tinged discharge or sudden loss of balance, needs urgent evaluation before any ear cleaner is used, since some products can worsen damage behind a ruptured drum. Discharge alongside a head tilt, stumbling, or a very painful ear that the animal will not let you touch also warrants same-day care.

What the Vet Will Do

The vet examines the ear canal with an otoscope to check for foreign material, a mass, or damage to the eardrum. A sample of the discharge examined under a microscope quickly identifies whether mites, yeast, or bacteria are driving the problem, which guides the choice of treatment. Chronic or recurring cases may need imaging to check whether the infection has spread to the middle ear.

Home Care and Prevention

Clean visible debris from the outer ear with a vet-approved cleanser, but never insert cotton swabs deep into the canal. Dry ears thoroughly after swimming or bathing, especially in breeds with floppy or hairy ears. Treat underlying allergies, since ears that keep flaring up despite treatment often point toward an allergy that needs its own management plan. Routine ear checks catch wax buildup, mites, or early infection before discharge becomes heavy or painful.