Ear infections (otitis externa) are a common occurrence in our pets and can cause scratching, rubbing, and head shaking. Some pet owners will notice a dirty ear that needs to be cleaned all the time. A normal, healthy ear needs no intervention, so a build up of wax means something is wrong.
The outer ear is basically a tube of skin with the eardrum at the bottom closing off the tube. The ear flap or pinna as we call it, comes in a variety of shapes, but in general has a furry outside and a less hairy inside. The skin of the ear and pinna is specialized and produces wax to help protect the ear. The skin cells grow in a way that moves them up and out to keep the ear naturally clean, but even the cleanest ear is not a sterile place. Bacteria and other organisms live in balance on the skin layer. When your pet gets an ear infection this balance is disrupted, allowing yeast and bacteria to flourish. This overgrowth results in what we see as an infection.
So, what conditions allow the organisms to take over? Warmth and moisture favor growth, as does a build up of wax and dead layers of skin. Inflammation of the ear is the biggest factor that leads to infections. Anything that can affect your pet’s skin can also affect the ears. Remember that the ears are made of skin. Think of a skin rash, and roll it into a tube. Wax and dead skin cells build up and the tube gets narrower due to swelling. The most obvious change is a red, sore looking ear, but there can be other symptoms as well:
a build up of brown wax
discharge that makes the ear sound like it is wet
a bad odor
a change in texture to the inside of the ear flap causing a rough or bumpy feeling
scrapes, scabs and blood caused by excess scratching
decreased hearing is uncommon, but possible
Thankfully, most pets will have very few ear infections in their lives. Once we establish an infection, I can take samples from the ears to look at which organisms are growing. This ensures I can pick the best medication suitable for the infection. We often will clean the ear here before prescribing an ointment. At the end of the treatment, I recommend a follow-up visit to look down inside the ear canals to make sure everything is back to normal.
Unfortunately, some animals will get recurrent infections. With these pets, it is important to get to the root of the problem and address the underlying issues. Anything that causes itchy skin will potentially bother the ears. Allergies, either seasonal or year round, are a major contributing factor to ear inflammation. Sometimes itchy ears are the only sign. Biting insects such as fleas, mosquitoes and earmites are obvious irritants. Wet ears from swimming, summer humidity, even the natural shape of an ear flap can facilitate infections. For these pets, clearing up the infection is just the start. Working out a management strategy to prevent frequent infections is the key to long term relief.