Primary secretory otitis media is an uncommon condition that occurs primarily in Cavalier King Charles Spaniels. It is due to the accumulation of mucus within the tympanic bulla.
Although otitis media usually develops as an extension of otitis externa or when pharyngeal microorganisms migrate through the auditory tube, primary otitis media can occur. This uncommon condition presents most often as primary secretory otitis media (PSOM).
PSOM has been reported in Cavalier King Charles Spaniels and other small brachycephalic breeds. PSOM has only been reported in dogs.
Males and females seem to be affected equally by PSOM. Age at diagnosis is typically 3–7 years.
Clinical Findings of Primary Secretory Otitis Media
Clinical signs of primary secretory otitis media in dogs include the following:
guarded neck carriage
otic pruritus without otitis externa
spontaneous vocalization
Horner syndrome
facial nerve palsy/paralysis
ipsilateral head tilt
seizures
keratoconjunctivitis sicca
impaired hearing
fatigue
concurrent otitis externa
PSOM may be unilateral or bilateral.
Dogs with PSOM present with the typical clinical signs of otitis media; however, they may also have guarded neck carriage, otic pruritus without otitis externa, and spontaneous vocalization.
The clinical signs of PSOM also overlap with those of syringomyelia, which is more common in Cavalier King Charles Spaniels.
Diagnosis of Primary Secretory Otitis Media
Visualization of bulging pars flaccida on otoscopic examination
Advanced imaging (CT or MRI)
Primary secretory otitis media may be suspected on the basis of history and physical examination.
In a Cavalier King Charles Spaniel, a bulging pars flaccida on otoscopic examination is highly suggestive of PSOM. However, not all cases can be identified by otoscopic examination alone.
If PSOM is suspected and a bulging pars flaccida is not visible on otoscopic examination, advanced imaging (CT or MRI) should be done to evaluate for the presence of soft tissue material within the tympanic bulla.
Treatment of Primary Secretory Otitis Media
Myringotomy and removal of mucoid debris
Total ear canal ablation in refractory or recurrent cases
Treatment of primary secretory otitis media is aimed at mechanical removal of the mucoid debris in the tympanic bulla. This is best achieved through myringotomy, followed by a combination of gentle flushing and suction to remove mucus.
Although PSOM is generally a sterile condition, the removed material should be submitted for bacterial culture and susceptibility testing to guide the selection of antimicrobial therapy, if warranted.
In dogs with recurring clinical episodes of PSOM, myringotomy may need to be repeated; in refractory cases, total ear canal ablation may be required.
Key Points
Primary secretory otitis media occurs primarily in Cavalier King Charles Spaniels.
Clinical signs are similar to those of classic otitis media but also include guarded neck carriage, otic pruritus without otitis externa, and spontaneous vocalization.
Diagnosis requires otoscopic examination and, if possible, advanced imaging.
Treatment with a myringotomy provides temporary relief but may need to be repeated.
For More Information
Cole LK, Samii VF, Wagner SO, Rajala-Schultz PJ. Diagnosis of primary secretory otitis media in the cavalier King Charles spaniel. Vet Dermatol. 2015;26(6):459-466.
Cole LK. Primary secretory otitis media in Cavalier King Charles spaniels. Vet Clin North Am Small Anim Pract. 2012;42(6):1137-1142.
Stern-Bertholtz W, Sjöström L, Håkanson NW. Primary secretory otitis media in the Cavalier King Charles spaniel: a review of 61 cases. J Small Anim Pract. 2003;44(6):253-256.
