Otodectes spp
From Felipedia
Ear mites, caused by Otodectes cynotis is a common parasite of cats, resulting in the skin disease otitis externa.
Ear mites are a common parasite of the cat, responsible for causing otitis externa.
Infection is normally attributed to cat's habit of lying in warm wood shavings under trees, where the mites normally live. Otodectes infection is relatively contagious due to cat's proclivity of sleeping together. Otodectes spp infection in cats occurs worldwide, accounting for up to 25% of consultations in feline dermatology[1]. Transmission is by direct contact and occurs most likely in the neonatal period. Young animals are therefore more susceptible. This mite is not host-specific and also causes otitis externa in the dog and ferret. Transmission to humans may cause pruritus of the arms and trunk[2].
Diagnosis
Mites are usually found deep in the external ear canal, but occasionally are seen on the body.
Clinical signs include head shaking, continual ear scratching, and ear droop. Pruritus is variable. Purulent inflammation and discharge of the external ear (otitis externa), and possible perforation of the tympanic membrane may be seen in severe cases (otitis interna). Pruritus is usually severe, likely to be attributed to hypersensitivity by immunoglobulin E antibodies directed against antigens released by the mite. Self-induced erosions are observed around the ears and aural haematoma are often seen. If the tympanic membrane is ruptured, vestibular syndrome is sometimes observed. Non-specific pruritic lesions on the face, neck and dorsolumbar region, presenting as miliary dermatitis or symmetrical alopecia, are typical. Sometimes, the body is affected without involvement of the ear canals[3].
Other causes of facial pruritus may need to be excluded in the diagnosis.
Treatment
Affected animals should receive appropriate parasiticide treatment in the ears and on the whole body for 2-4 wk.
- Ivermectin has shown reliability over the years, applied topically to ears or used systemically.
- Spot-ons such as Revolution, Frontline or Advocate applied as a single drop to ear is effective as a simple therapy in most cats.
