This spring, Amex, an elderly Corgi, came in for her annual visit. During her long, otherwise carefree life, Amex has been plagued by skin and ear problems. When she was younger, we had diagnosed several underlying conditions including hypothyroidism and food and inhalant allergies. These chronic issues made her predisposed to dermatological difficulties including inflammation of her ear canals.
Despite long-term treatment, over the years we had resigned ourselves to the fact that, now and then, Amex’s ears flare up. Technically called otitis, not every case of inflamed ears is caused by infection, and not every infection is caused by the same organisms, but most veterinarians, myself included, usually just reach for one of a number of common commercial preparations to treat run-of-the-mill inflamed ears. These products contain various combinations of antibiotics to fight bacterial infection, antifungals to fight yeast, and anti-inflammatories to reduce irritation. Since it’s estimated that 20 percent of all dogs in the United States have otitis, that’s a lot of Panalog, Otomax, TriOtic, Animax, Tresaderm, etcetera.
Amex’s owners had used many of these preparations intermittently. Sometimes it helped. Sometimes not. Sometimes her ears cleared up for months, but eventually the otitis would always recur. Her dad amiably accepted the situation and after a while, we fell into the habit of just grabbing one of those standard medications when necessary and accepting a less-than-ideal resolution to the situation. But this time, this year, her ears looked…well…really, really yucky.
Since I’m not supposed to write things like “really, really yucky” on medical records, I jotted down “copious greenish-black discharge a.u.” on the page, a.u. being doctorspeak for both ears. “These look nasty,” I blurted out, and began swabbing goo from her canals.
Many popular Island breeds, like golden retrievers and Labradors, are prone to otitis, as are cocker spaniels, springers, and poodles, but any dog can be afflicted. Anything causing poor ventilation of the ear canal makes otitis more likely. Dogs with floppy ears. Dogs who swim a lot. Anatomically narrow ear canals, or excessively hairy canals, or excessive wax production. Dogs like Amex with allergies or hypothyroidism. All these increase the risk.
A pooch with otitis will often shake her head, scratch, or cry when you rub the affected ear, but some dogs act stoically normal. Your veterinarian can see if the ear is red and inflamed by looking inside. Sometimes it is obvious. Sometimes we need to look deeper in with an otoscope. Sometimes we need to evaluate the discharge with a microscope to better determine what is causing the problem. “I want to do cytology on this,” I said, rolling a smear of goo onto a slide.
I love my microscope. My mother started her career as a junior high school biology teacher and we always had a microscope knocking around our house when I was a kid. She often brought home other interesting stuff — like the cow’s heart she got from the butcher to teach anatomy class. I remember playing with it, sticking it under the faucet, watching water flow in and out of the various chambers and vessels. That was fun.
My favorite childhood microscope activity? Observing paramecia in pond scum. For me, sitting down at the microscope with a slide of ear goobers gives me the warm, fuzzy feeling normal folks get from the smell of freshly baked cookies.
So there I was, happily looking at Amex’s slide. A little bacteria or yeast can be normal, but here were more organisms than I like to see. Yeast. Cocci bacteria — probably just your average, garden-variety staphylococcus, or maybe strep. All these are usually susceptible to common medications. I kept looking. Skin cells. That’s normal. Hold the phone. Looky here. Tons of PMNs. That’s polymorphonucleocytes. That’s an eight-syllable word for pus. Pus is not good. And finally another kind of bacteria, shaped like tiny rods. Aha.”Looks like a pseudomonas infection,” I pronounced.
Pseudomonas can be notoriously difficult to cure so I suggested a culture and sensitivity to help us make the best treatment plan. Taking a sample from the ear with a sterile swab, we sent if off to the lab. They would grow, then identify, the bacteria and determine which antibiotics were most likely to be effective. “In the meantime, I’m mixing you up a special brew,” I said. The wall of pseudomonas bacteria is incredibly tough. Even the “right” antibiotic sometimes simply can’t penetrate it. We needed Tris-EDTA. This ingredient weakens the bacterial wall, allowing the antibiotic to get inside and kill the bug. “Give a big squirt in both ears twice a day until the culture results are back,” I concluded, handing dad a bottle of Tris-EDTA mixed with an antibiotic.
The culture confirmed Pseudomonas and Streptococcus. Amex’s ears were improving slowly with our new medications. Her dad brought her in week after week for me to clean her ears and check her progress. After a while, we added oral antibiotics. There was improvement, but she still was not right. We added oral cortisone to reduce inflammation. Improving, but still not right. We tried an additional topical medication supposed to be particularly effective for Pseudomonas. Week after week. Improving but still not right.
“I can’t believe I’m gonna suggest this,” I said after looking at another slide and still finding rod bacteria, “but these ears really should be 100 percent better. I want to repeat the culture and sensitivity.” God bless him, her owner agreed. When the results were in, we had our explanation. Over the course of our treatments, the Pseudomonas had become resistant to the antibiotics we were using. We changed our treatment plan yet again, based on the new test results.
Last week Amex came in for another recheck. Her ears looked good. Really, really good. Now that’s something I can write on her medical record. Her master gets all the credit for persisting with the recommended diagnostics and rechecks until we could discover the right treatments.
All this veterinary care? Time-consuming and expensive.
Seeing those beautiful, clean, infection-free ears? Priceless.
