Ear Infections

A very common problem in dogs and cats is ear infections. There are many different causes and numerous treatment regimens to affect a cure. Since the causes tend to be multifactorial we need to address all of them for a successful outcome.

Hygiene is of major importance both in curing the problem and prevention of recurrence. Ear infections can easily become chronic in nature, so proper therapy early in the course of the disease is important, along with long term commitment to keeping the ears clean.

Long term problems with the external ear can progress to problems with middle (otitis media) and inner (otitis interna) ears. This can cause substantial pain, equilibrium problems, and even hearing loss.

Anatomy

Dogs and cats ears differ from human ears in several significant ways. The main difference is the shape and length of the ear canal. It is longer in animals and has a downward and then inward direction. Cleaning them requires more effort than in people.

This picture shows normal dog and cat ear canal anatomy. The arrows show the downward and inward path of the external ear canal. The tip of the arrow to the left is pointing to the ear drum. When you clean the ears you will gently be pulling up on the external ear to straighten this canal out and allow deeper penetration of medication.

Symptoms

Pets commonly give their owners a clue that their ears are bothering them. Most pets will either have discharge, odor, or will be shaking their head. Sometimes the ear flap will become extremely swollen-this is called an aural hematoma. Pets that have a foreign body in their ear like a fox tail will be shaking their head extensively and frequently paw at the affected ear.

Causes

Ear disease is caused by many different and predisposing factors, some of them working in combination:

• Anatomy-deep ear canals and long floppy ears are predisposing causes because they set up a warm and moist environment that bacteria and fungi thrive in.
• Breed- Some breeds like Cocker Spaniels are commonly affected because of allergies, long floppy ears, and inbreeding.
• Allergy- In addition to causing itchy skin and hair loss in general, allergies can also cause ear problems. Food allergy is a common cause and sometimes even flea allergy.
  
• Low Thyroid- On occasion low thyroid hormone can cause ear problems
• Parasites- Ear mites are also a cause of ear disease, especially in cats. Also chiggers and sometimes ticks.
  
• Drug reactions- Any drug can cause a reaction that inflames the ear, including some cleaning agents.
  
• Hygiene- Debris in the ear canal can cause an infection
• Auto immune system diseases
• Tumors
• Sugar Diabetes
• Cushing's Disease
• Feline Leukemia (FeLV) and Feline Immunodeficiency (FIV) viruses
• Canine Distemper
• Bacteria- Staph, Strep, Proteus, E. coli, and especially Pseudomonas
• Excessive cleaning
• Yeast- Candida and Malazzezia
• Foreign bodies- debris, hair, foxtails (plant awns)
  

Diagnosis

Since there are many causes to ear disease an accurate diagnosis is essential to relieving the problem. Several diagnostic tests are routinely used:

A routine physical exam is used on every pet that is presented with ear problems because ear infections can be a sign that there are problems elsewhere in the body. This exam is an essential part of the Diagnostic Process, and might include routine blood work.

Ear swabs are used to obtain a sample of discharge for microscopic analysis

Microscopic analysis of the discharge helps us determine if your pet's problem is bacterial or fungal related. This analysis is performed in our office by taking some of the discharge from the ear canal, staining it blue with a special stain, and observing how many bacteria or fungi are noted.

A culture of the discharge from the ear is sometimes used as an aid to determine what bacteria or fungus is causing the problem. Since many organisms are usually grown in a culture, and some of them are normal inhabitants, this test is not always advantageous. This picture shows a culture that grew out 3 different bacteria that are common to find in the ear canal. Organism #2 (Pseudomonas) is resistant (R) to all the antibiotics that are commonly tested.

The otoscope is an important tool that allows us to visualize the anatomy of the external ear canal, including the ear drum. It is also used to retrieve foreign bodies, usually foxtails, from the ear canal, and to check for tumors.

Checking for proper thyroid level is an important test in every dog that has recurring problems, especially in Golden Retrievers. This is a report from a pet that has a normal thyroid level.

In addition to these tests allergy tests are utilized when they are suspected as the cause of the problem. A blood sample is taken that tests for allergies to food, commonly found material inside of your house, and plant like materials found throughout our area in the outdoors. Your doctor will let you know if this test is needed.

Treatment

Each ear infection requires specific treatment depending on the results of the physical exam and diagnostic tests. If there are underlying problems your doctor will prescribe medication to prevent them. In the overwhelming majority of cases medical care is all that is needed. Surgical correction of an ear infection is usually used only after medical care has been unable to control the problem.

For the majority of ear infections proper cleaning and routine topical medication will correct the problem. Learning how to clean your pet's ears is crucial. Once you have an ear infection under control, which takes 3-7 days in most cases, your goal should be to clean your pet's ears once or twice each week in order to prevent recurrence. Infections that continually recur are very painful and substantially decrease your pet's quality of life.

Your doctor will routinely prescribe two medications. The first is used to gently clean the ear canal and remove debris and infection. The second medication is a combination preparation that kills either bacteria, fungi, or parasites. These medications usually contain an anti-inflammatory preparation to soothe the ear also. Occasionally your doctor will prescribe oral medication to clear up the infection and to decrease the inflammation in the ear canal.

Many dogs have hair inside of the ear canal. This hair is removed to facilitate cleaning and to let air circulate into the ear canal. This should be done routinely, which for most dogs is once monthly. These ears are typical of a pet that needs the hair removed from its ears and a thorough cleaning.

These are the same ears after one of our nurses has cleaned them. It is obvious from the picture that this pet will feel much better from this treatment.

In some pets the ears are so inflamed that its painful to clean the ears. In these severe cases we use sedation and flushing. A warm cleansing solution is used to remove debris and infection from deep within the ear canal by flushing action only. These ears are painful and we need to go gently so as not to cause more pain and damage to an already severely inflamed ear canal.

This ear has had recurring infections for so long that it is no longer possible to clean the external ear canal. The canal is swollen shut, infected and very painful. The only adequate remedy in this case is surgical correction to completely remove the ear canal. It is extensive surgery and requires a surgeon with specialized training and expertise. The goal of long term ear care is to never let the disease progress to this point.

Here is another dog with the same problem as it is prepped just prior to surgery

In many mild cases we are able to clean the ears in our office without sedation. After we perform the initial cleaning in our office your job at home will be much easier. You will need to clean them at home to affect a cure and prevent recurrence. Our nurses will demonstrate exactly how to do this with your pet. To learn the technique click here.