When we think about common health issues in cats, otitis externa and media don’t usually come to mind. However, according to Douglas DeBoer, a renowned professor of dermatology at the University of Wisconsin School of Veterinary Medicine, feline otitis can be subtle and challenging to manage. In this article, we’ll delve into the unique characteristics of feline otitis and explore strategies for effective treatment.
Cat Ears: Not Small Dog Ears
Unlike their canine counterparts, cats are less prone to otitis. However, when feline otitis does occur, it presents some intriguing idiosyncrasies. Anatomically, there are differences between the middle ears of cats and dogs. While dogs have a single compartment in the tympanic cavity, cats have a nearly complete septum that divides the cavity into two distinct compartments. This separation can impede drainage and lead to occlusion, making feline otitis particularly challenging.
Furthermore, the aural microbiome in cats differs from that of dogs. While certain bacteria and yeast species are commonly associated with otitis in dogs, the same cannot be said for cats. In a study of stray cats, the cytology of feline otitis revealed various microorganisms, including Staphylococcus, Otodectes, Malassezia, and rods, highlighting the diversity of pathogens involved.
External is Not Eternal
When diagnosing feline otitis, it is crucial to rule out foreign bodies and polyps through otoscopy. Thorough ear cleaning is then necessary to remove ceruminous debris. However, caution must be exercised when flushing the ears if the tympanic membrane is ruptured. It’s important to avoid using ototoxic substances like chlorhexidine in these cases.
Thankfully, feline otitis can often be effectively managed with aminoglycoside/steroid combinations such as Tresaderm or Mometamax. While not specifically approved for cats, florfenicol formulations like Claro and Osurnia have also shown efficacy in the treatment of feline otitis. Dr. DeBoer has successfully utilized these off-label treatments in cases where cytology indicates certain pathogens and treatment compliance is a concern.
In cases of recurrent otitis, there are several potential underlying factors. These include poor owner compliance, the presence of antimicrobial-resistant organisms, allergies, atopy, ear canal stenosis or occlusion (such as polyps), or even otitis media.
The Middle Ground: Otitis Media
Otitis media, or middle ear infections, differ in pathogenesis between dogs and cats. While dogs often develop otitis media as a result of “descending” bacteria from otitis externa, feline middle ear infections are more frequently secondary to “ascending” inflammatory or infectious diseases of the Eustachian tube and nasopharynx. Common upper respiratory infections like feline herpesvirus and calicivirus can contribute to feline otitis media.
Dr. DeBoer emphasizes that feline otitis media is more prevalent than previously realized and may explain some of the unusual clinical signs seen in cats. These signs may include clumsiness, head shaking, pawing at the ears, discomfort when opening the mouth, changes in eating habits, hearing loss, depression, and even overt neurological symptoms like Horner’s syndrome, head tilt, nystagmus, ataxia, and obtundation.
Feline otitis media can affect one or both ears, and it can sometimes be secondary to recurrent otitis externa.
Studies Shed Light
Several studies have shed light on the prevalence of middle ear disease in cats. A retrospective review of skull computed tomography (CT) studies performed on 310 cats revealed middle ear disease in 101 of the patients. Surprisingly, only 26 of these cats had been imaged specifically for suspected middle ear disease. In another study, 48 out of 100 ears from 50 feline necropsies showed evidence of ongoing or previous otitis media.
To properly diagnose otitis media, the workup typically begins with ear swab cytology. In cases of recurrence, imaging under anesthesia and culture are recommended. Myringotomy, the incision of the eardrum, may be necessary to facilitate culture, and middle ear irrigation is often performed. Treatment involves topical and systemic antimicrobials, along with supportive care.
In some cases, when medical management fails, surgery may be required. Ventral bulla osteotomy or total ear canal ablation are potential surgical options. However, Dr. DeBoer emphasizes that medical management can be successful, and surgery should not be the immediate go-to solution.
To the Future
Feline otitis presents unique challenges due to the distinct characteristics of cat ears and the diversity of pathogens involved. However, with a comprehensive understanding of the condition and appropriate management strategies, veterinarians can effectively overcome these challenges. By leveraging both medical and surgical approaches, a brighter future awaits our feline friends plagued by otitis.
Remember, if you ever need professional care for your feline companion, reach out to Katten TrimSalon for expert assistance.