Overview of Chronic Ear Infections in Cats
Otitis is an inflammation of the ear and it is one of the most frequent reasons for owners to seek a veterinarian's help. The prevalence of otitis externa, or inflammation of the external ear, in cats has been reported to be between 10 to 20 percent although in more tropical climates it is probably closer to 30 to 40 percent.
The term otitis does not refer to a specific disease, but it is a symptom of many diseases and not a specific diagnosis.
Chronic inflammation stimulates the proliferation of the skin lining the ear canal. As a consequence, thickening of the canal occurs and leads to narrowing of the canal. More importantly the skin is thrown into numerous folds, and this inhibits effective cleaning and the application of medications. These folds act as a site for the perpetuation and protection of secondary micro-organisms like bacteria.
Inflammation of the middle ear (otitis media) results from chronic inflammation of the external part of the ear canal, rupture of the ear drum and establishment of infection in the middle part of the ear. Discharge in the tympanic cavity is difficult to treat with topical therapy and often remains as a source for infection. Otitis media is usually bacterial in origin. Clinical signs suggestive of otitis media include head shyness and pain on palpation of the ears. Some cases of otitis media might experience head tilt, circling and dry eyes, but the vast majority do not have neurological abnormalities.
As the ear drum quickly grows back after rupture, otitis media may also be present, even if an intact membrane is seen on otoscopic examination. Radiography cannot be used to completely rule out the presence of otitis media since 25 percent of confirmed cases had no radiographic evidence of the disease. In one study, otitis media was present in 80 percent of cases of chronic, relapsing otitis externa, so it must be considered as a possible cause of any refractory or relapsing otitis externa. Treatment of otitis media is based on bacterial culture and sensitivity results. Most cases require long term antibiotic therapy, a minimum of 2 months, and aggressive topical therapy.
Diagnosis of Chronic Ear Problems in Cats
The identification of the underlying disease responsible for the chronic ear disease is of crucial importance. In order to do this it is important for your veterinarian to:
Treatment of Chronic Ear Problems in Cats
Regular cleaning at home is an important part of the therapy. Several products can be used.
In-depth Information on Chronic Ear Infections in Cats
Most cases (over 80 percent) of chronic or relapsing otitis externa have otitis media. This results from chronic inflammation of the external part of the ear canal, rupture of the tympanic membrane and establishment of infection in the middle part of the ear.
Discharge in the middle ear cavity is difficult to treat with topical therapy and often remains a source of infection. Otitis media is usually bacterial in origin.
Treatment of otitis media is based on bacterial culture and sensitivity results. Most cases require long term antibiotic therapy (minimum of two months) and aggressive topical therapy.
Most causes of otitis externa are associated with generalized dermatologic conditions. A complete dermatologic history and work-up may therefore be necessary in the diagnosis of many primary otitis externa cases. The most common causes seen in dermatology are atopy (inhalant allergies), food allergy, diseases of keratinization (e.g. primary seborrhea of cocker spaniels), and ear mites. It is critical to long term management of otitis externa that a primary cause can be found.
In-depth Information on Diagnosis of Chronic Ear Problems in Cats
In cases of ear inflammation, your veterinarian will want to identify and correct the primary underlying cause as well as the perpetuating cause (e.g. bacterial infection).
In-depth Information on Treatment of Chronic Ear Problems in Cats
Pseudomonas infections are extremely frustrating and difficult to treat. Most effective treatments include:
Therapy for ear mites can be topical or systemic. Topical treatments include milbemycin (Milbemite®), ivermectin (Acarexx®) or thiabendazole (Tresaderm®) in the ears or selamectin (Revolution®) as a spot on treatment to be applied in between the shoulder blades. Treatment should cover the cycle of the mites, which is three weeks. One single application of milbemycin, ivermectin or selamectin is usually sufficient to eradicate the infestation.
Cytology and culture should be performed monthly throughout the therapy and before discontinuation of antibiotic therapy. Early identification of the underlying cause and aggressive treatment of the infection are the only ways to prevent more serious and permanent damage in the ear canal.