This diagram of the ear canal may help you understand why some cases of otitis are very difficult to treat. The canine ear canal is not short and sweet like the human's. You can't see the ear drum with good eyesight and a strong light. It's a long canal and it has a severe bend. You can see in the diagram that it starts out going almost straight down, along the side of the head. Then it takes a left and goes straight into the head, where it ends at the ear drum.
We veterinarians talk about the "horizontal canal" (H) and the "vertical canal" (V) like they are two different structures. They are just different areas of the same tube that connects the hearing apparatus to the outside world.
In general, inflammation that is just in the vertical canal and the outside of the ear is easier to treat than disease in the horizontal canal. The problem with a lot of dogs is that the horizontal part of the canal tends to accumulate debris. When there is a yeast infection or a bacterial infection, the pus and yeast slime can completely clog the canal. Shoving a Q-tip into this plug can spell disaster, pushing it straight through the ear drum into the middle ear (ME). And using a Q-tip in here is like trying to unclog a sink drain with a baseball bat anyway; it feels good to try, but it just packs the clog in tighter.
Here are the fundamental steps in resolving most cases of otitis:
1. Find out what is causing the inflammation and stop it. In the meantime
2. Clean the ears
Click this link for detailed instructions on cleaning a dog's ears, illustrated with photos. The debris in the ear canal can act as a focus for further inflammation and irritation. It can also hide bacteria and yeast, prevent topical medications from contacting the skin, and inactivate the ingredients in the medications. When there is enough debris it can impede hearing. The choice of cleanser depends on the environment in the ear. Those with secondary yeast infections will require different cleaners than those with only inflammation, or with a bacterial infection.
3. Treat secondary infections
The secondary Malassezia (yeast) and bacterial infections can contribute significantly to the inflammation and itching in the ear. Bacteria in the ear are often resistant to common antibiotics. A swab should be taken for bacterial culture and antibiotic sensitivity testing before treatment is instituted. The medication selected should be based on the type(s) of bacteria grown and the results of the sensitivity tests. This is especially true of recurrent ear problems.
Antibiotics and antifungals are often applied topically in the form of ear ointments or creams. Some pets require oral medications as well. Oral medications penetrate the skin via the bloodstream and work from the inside out. Pets with middle ear infections will always need oral medications, as topical drugs cannot penetrate to the middle ear.
4. Decrease inflammation
Resolving inflammation will decrease pain, itching and swelling. When the ear canal is less inflamed pets will better tolerate cleaning and medicating. When the canal opening is wider, medications can get to where they need to go and debris can be more easily removed.
Anti-inflammatories may be present in ear ointments, or may be given orally. In dogs with moderate to severe ear disease a corticosteroid may be given for several days before ear flushing or cleaning is done, to alleviate some pain.
5. Find out what is causing the inflammation and stop it.