Susan F. Foster,     Murdoch, Australia

Geraldine Briony Hunt,     Davis, California

Clinical Signs of Nasopharyngeal Disease

Nasopharyngeal disease usually results in signs of upper airway obstruction, namely, inspiratory respiratory effort and stertor or snoring. In dogs, stertor is usually alleviated by open-mouth breathing. Cats are often unwilling or unable to breathe through the mouth and thus may exhibit severe respiratory distress. Pharyngeal discomfort, repeated attempts at swallowing, coughing, gagging, dysphagia, aerophagia, and changes in phonation also may occur. Animals with acute nasopharyngeal disease may paw at the nose and mouth or have facial discomfort and pruritus. Reverse sneezing is a specific nasopharyngeal sign in dogs. Sneezing is not typical of nasopharyngeal disease but may occur if the caudal nasal turbinates are irritated or if disease also affects the nasal cavity. Unless nasopharyngeal disease is accompanied by significant intranasal pathology, nasal discharge is usually mild or absent, because secretions from the nasopharynx tend to be swallowed. Purulent nasal discharge and fetid breath can be noted in animals with foreign bodies.

Signs of otitis media and vestibular disease can be seen when there is extension of disease from the nasopharynx into the tympanic bulla (or vice versa) or when the opening to the auditory (eustachian) tube is occluded. In one study, bullous effusion, considered most consistent with acute effusive disease, occurred in 34% of all cats with nasopharyngeal disease and 100% of cats with caudal nasopharyngeal disease (Detweiler et al, 2006). Thickening of the soft palate and reduced nasopharyngeal aperture have also been associated with the development of effusive otitis media in cavalier King Charles spaniels (Hayes et al, 2010). Conversely, expansile middle ear disease can cause nasopharyngeal obstruction. Horner’s syndrome is commonly encountered in cats with involvement of the tympanic bullae. Deafness and signs of otic pain may occur, and there also may be signs of facial nerve dysfunction. Occasionally, the main presenting signs are neurologic, resulting from the spread of infection (such as cryptococcosis) or neoplasia, or signs may be related to the gastrointestinal tract (megaesophagus or hiatal hernia).

The speed of onset and severity of signs are variable and depend on the cause. Sudden onset of signs is suggestive of a foreign body, whereas gradual onset of stertor and attempted mouth breathing is more typical of a slow-growing nasopharyngeal mass.

Diagnosis of Nasopharyngeal Disease

Surgical Access to the Nasopharynx

When extraction of lesions such as inflammatory polyps, cryptococcal granulomas, or foreign bodies is not possible via palatine retraction, or better access is required to obtain diagnostic samples, the nasopharynx can be approached surgically via a longitudinal incision in the soft palate. In most cases, adequate access is obtained by maximally opening the jaws, placing a mouth gag, and having an assistant hold the endotracheal tube out of the way with a malleable retractor. Operating in this area requires some experience, and most cases are best managed by referral to a surgical specialist.

The soft palate is divided longitudinally from the caudal edge of the hard palate to within a centimeter of its caudal free edge. The caudal edge should be left intact to facilitate repair and support the incision during healing. Bleeding from the rich vascular plexuses within the soft palate should be anticipated but usually resolves spontaneously or with digital pressure. When extensive dissection is likely to be undertaken in dogs, blood loss may be ameliorated somewhat by temporary occlusion of the carotid arteries using Rummel tourniquets placed through a ventral midline cervical incision. This technique is not recommended for cats because it can result in permanent neurologic sequelae. In either species, if major blood loss is anticipated, contingency plans for replacement with whole blood or blood components should be made. The surgeon also should have a variety of hemostatic methods available, including sterile gauze for temporary packing of the nasal cavity or nasopharynx, and an implantable product such as Gelfoam. The soft palate incision can be continued rostrally as a mucoperiosteal incision and ventral rhinotomy if indicated, to provide excellent access to the ventral nasal cavity. Two- or three-layer repair of the soft palate with polydioxanone in a continuous suture pattern in the nasal mucosal and muscularis layers and in the oral mucosa provides excellent closure. Postoperative management is usually uncomplicated: animals display little evidence of pain and usually eat and drink within 24 hours of surgery unless systemic illness is present. Healing in this area is rapid and reliable, presumably due to the excellent blood supply. Soft food should be offered for 2 to 3 weeks after surgery and the incision examined at weekly intervals for signs of wound dehiscence.