Ear mites, caused by Otodectes cynotis is a common parasite of cats, resulting in the skin disease 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.

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).

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.