Ear infections are a very common malady for our canine companions. There are three types of infection all defined by the location in the ear. Otitis externa is an infection involving the ear canal to an intact ear drum. Otitis media is an ear infection involving the middle ear between the ear drum and the inner ear. And Otitis interna is an infection involving the inner ear. The most common is otitis externa. If the ear drum ruptures then the pet has both otitis externa and otitis media.
Ear infections are very frustrating issue with our human clients. The reason they are both frustrating and common is (sit down before you read the rest) ear infections are not curable. Ear infections can be treated and managed, but they are not curable. The reason for their incurableness is the underlying causes for the ear infection.
There are many underlying reasons the ear canal will get infected. The infection is just the result of the underlying causes, not the cause itself. For example, you have a swollen red infected finger. The finger swelling and infection could have been by the cat bite, the splinter, or a cut and the infection was the result. Same goes for an ear infection. Identifying the underlying causes and managing them will make for happy pet and owner.
The first underlying reason is the anatomy of the ear canal. We all have a hole at the beginning of the ear canal. A human ear canal continues horizontally to the ear drum. A dog’s ear canal travels down (vertical ear canal) about ¾ inch then turns horizontal about ½ inch to the ear drum. Any wax, water, dirt, or whatever will drop down the canal. The second anatomical problem is hairy ear canals. Certain breeds like Poodles and Schnauzers have exceptionally hairy ear canals trapping any wax, dirt, or moisture. Certain breeds like Spaniels and Bassets have floppy ears that cover the opening allowing body heat and moisture to aid the bacteria and yeast to flourish. Certain breeds like Shar Peis have extremely small ear canals making it harder to thoroughly cleanse the ear.
The second underlying reason is moisture. Baths, swimming, ear licking, rain and humidity will cause moisture to build up in the ear canal. In people we commonly call this condition swimmer’s ear. And we know of the consequences if we do not remove the moisture. In our pets, the moisture and body heat create the perfect environment for an infection to fester.
The third most common underlying reason for ear infections is allergies. Pets that have allergies have common symptoms. Those symptoms are itchy skin and the most common areas are the feet and ears. The constant head rubbing, scratching and shaking abrades and inflames the skin causing swelling and redness. That swelling and redness creates a perfect environment for infection. Why do you think people with nasal allergies get sinusitis? The environment of inflamed mucous membranes and surface bacteria create the infection.
The lesser common underlying reasons are parasites like ear ticks and ear mites. Another underlying reason can be foreign objects stuck in the ear like toys and grass awns.
How do veterinarians approach ear infections? First and foremost is the gathering of history. Historical questions of reoccurrences, baths, and or swimming help narrow down some of the underlying reasons. Next step is the examination. Most ear infections are painful, so a decision needs to be made on how to examine a painful ear. A lot of times, the pet will need to be sedated to thoroughly examine the ear. Under sedation and/or anesthesia we first take a sample of the exudates (the accumulated debris in the ear canal) to examine under the microscope. Then the ear can be cleansed by gentle flushing with warm betadine solution. Once cleansed, we look at the entire ear canal down to the ear drum.
The material examined under the microscope will tell us if our infection is bacterial and/or yeast. This information helps us pick which medication we need to treat the secondary infection.
- Identify underlying causes for the ear infection.
- Allergies need long term systemic medications of prednisone or antihistamines to control the allergy.
- Moisture from baths, swimming, or humidity need to be controlled with ear cleansers that dry the ear canal.
- The pet’s anatomical problems will need to be addressed. Hair ear canals need to be plucked. Floppy ears need to be cleansed with a cleanser that will dry the ear canal. Small ear canals may have to have a surgery.
- Ear parasites need to be treated and prevented.
- Identify the infection. If the infection is yeast called Malassezia then an antifungal will be prescribed topically and/or systemically. If the infection is a bacterium then the appropriate antibiotic will be prescribed topically and/or systemically.
- Treat the pain. Most ear pain is caused by inflammation. It is very common to give the pet an anti-inflammatory drug, usually a steroid.
- Show the owner how to flush the ears at home and administer the medication.
- Recheck, recheck, and recheck.
The very serious ears will need surgery. Serious ear problems are extremely painful ears, dogs that are head shy from constant treatment, and/or small ear canals from chronic infection or breed related. This particular surgery is called a lateral ear resection. Very chronic ear infections may have the ear canal so swollen with scar tissue and inflammation that the only option is to remove the entire ear canal, called an ear ablation.
Question: I get a call from a client, “Hey Doc, I need a refill of Buster’s ear medicine you prescribed several months ago.” What is wrong with this scenario? Obviously I did not do a very good job of telling the owner about controlling the underlying conditions; the infection is just a result of those conditions and not the cause.
There are two important considerations with repeated ear infections:
- Scar tissue is laid down in the canal narrowing the canal like calcium in water lines. Making it harder to clean out the canal and treat. Eventually the ear drum will rupture and surgery becomes the only options. Ruptured ear drums cause the infection deeper into the ear. If the infection reaches the inner ear, hearing and balance are greatly affected.
- Constant antimicrobial treatment makes for resistance to the microbes you are treating. Soon, there are no medications effective against the super-bugs.
All ears can be treated and helped. Identify the underlying reasons and all ear infections will be held at bay. Or ignore the underlying reasons and the ear will be infected again. All that time and money spent treating the last infection will be lost as if you did not do anything at all. Helping you control your pet’s ear problem makes for a happy pet.