What are otodectic mites? - briefly
Otodectic mites are tiny, blood‑feeding ectoparasites that colonize the external ear canal of dogs, cats, and occasionally humans, leading to inflammation, itching, and secondary infections. They spread by direct contact and are controlled with topical acaricides or systemic antiparasitic drugs.
What are otodectic mites? - in detail
Otodectic mites are obligate ectoparasites that inhabit the external ear canal of mammals, most commonly domestic dogs and cats. Belonging to the family Psoroptidae, the species Otodectes cynotis is the principal agent of ear mite infestations. Adult mites measure 0.3–0.4 mm, possess a dorsoventrally flattened body, four pairs of legs, and chelicerae adapted for scraping skin debris.
The life cycle proceeds through egg, larva, nymph and adult stages. All phases occur on the host’s skin surface; no free‑living stage exists. Development from egg to mature adult requires 2–3 weeks under optimal temperature (25–30 °C) and humidity. The reproductive capacity is high, with a single female laying up to 30 eggs daily.
Typical hosts include:
- Dogs
- Cats
- Ferrets
- Rabbits
- Occasionally wildlife (e.g., foxes, raccoons)
Transmission occurs via direct contact between infested and susceptible animals. Mites can survive off‑host for only a few days, limiting indirect spread.
Clinical manifestations are confined to the ear canal:
- Intense pruritus leading to head shaking and scratching
- Accumulation of dark, waxy debris (cerumen) containing mite bodies and feces
- Inflammation of the tympanic membrane, potentially progressing to otitis externa
- Secondary bacterial or fungal infections due to skin damage
Diagnosis relies on microscopic examination of otic debris. A few drops of mineral oil placed on a microscope slide can clear the material, revealing characteristic oval bodies with dorsal shields and short legs.
Effective management combines acaricidal therapy with environmental control:
- Topical products (e.g., selamectin, moxidectin, ivermectin formulations) applied to the ear canal or skin
- Systemic medications for severe infestations
- Thorough cleaning of the ear canal to remove debris
- Treatment of all animals sharing the environment, even if asymptomatic
- Washing bedding, toys, and grooming tools with hot water or applying appropriate disinfectants
Prevention focuses on regular ear inspection, especially in multi‑animal households, and routine administration of prophylactic ectoparasiticides. Proper hygiene and prompt treatment of affected individuals reduce the risk of recurrence and limit spread within a population.