Recurrent otitis externa in dogs: cytology and rechecks

Bruno is a six-year-old neutered male Cocker Spaniel. [1] He had recurrent otitis externa for about four years, since two years of age; it resolved with treatment but came back in a couple of months. [1] His current infection was just not resolving with therapy. [1] Cytology showed a decent number of rods, with inflammatory cells. [1] His ears contained waxy debris and exudate, with hyperplastic glands and somewhat narrowed ear canals. [1] The presenter did not see large proliferations. [1]

What can the presentation and examination reveal?

Presentations range from just head shaking or just discharge to ear pain with head tilting. [1] Acute and chronic cases usually involve different bacteria, a distinction the presenter asks clinicians to consider. [1] The presenter describes otoscopic examination as absolutely necessary and says it can help identify treatment options. [1] Looking may reveal a large mass or a foreign body. [1]

In his experience, a blood-filled canal or frank blood coming from the ear makes a mass probable. [1]

What do rods change about product selection?

The presenter was unsurprised that it had not worked while rods remained present. [1] His explanation distinguishes the acute coccal infections these products are intended for from infections with rods. [1]

• Recognize that the products discussed are intended for acute otitis externa involving cocci, such as staphylococci. [1]
• If you have rods, those products are probably not going to work. [1]
• Avoid those products when rods are present unless there is no other option, as the presenter recommends. [1]

Note that the long-acting products named in this discussion—Osurnia, Claro and Simplera—all contain florfenicol. [1]

Why can the initial examination need a recheck?

The otoscopic exam is sometimes not the easiest thing to do because there is so much debris or exudate in the canal. [1] You might have to recheck it in two or three weeks to see how it looks afterwards. [1] That repeat examination may be used to look for a primary cause or evaluate whether the problem has resolved. [1]

The presenter describes either filling the ear canal and plugging it with a cotton ball or saturating a cotton ball and pushing it into the canal. [1] He likes the turbulence produced when the plugged canal is massaged, and owners can see the material on the removed cotton ball. [1]

What remains when the ear looks better?

An ear can look clinically improved while debris remains stuck deeper in the canal. [1] The presenter emphasizes that the problem will not be resolved until that remaining material is gone. [1]

The presenter describes an adherent, thick, slimy discharge in ears. [1] He thinks of these as preventing antibiotics from reaching the bacteria. [1]

Related lectures

On-demand lecture

Everyday Dermatology: Practical Approaches to Feline Pruritus, Canine Atopy, Otitis & Pyoderma

References

• Dr. Jason Pieper: Everyday Dermatology, Practical Approaches (lecture recording, Nov 15 2025) Vet On It lecture transcriptLecture source retained by Vet On It.