Signalment: 8-year-old male castrated Terrier mix (10.3 kg)
Presenting Complaint: sneezing and gagging for 1.5 weeks prior to presentation which progressed to nasal congestion.
History: Initial clinical signs included sneezing followed by gagging. At night nasal congestion was noted by owners. Initial medical management included enrofloxacin and Neo-Poly-Dex drops administered intra-nasally. No improvement noted and a nasal flush 1 week later flushed out mucoid nasal discharge. Increased frequency of sneezing and nasal discharge was noted after the nasal flush. Eating more slowly since the nasal disease started.
Medications: enrofloxacin (68 mg once every 24 hours)
Physical Exam Findings: Completely absent airflow from the left or right nostril with open mouth breathing. Bilateral mucopurulent nasal discharge.
Complete blood count: WBC 23.88 K/ul. (54.3 % Neu, 32.6 % Lym).
Thoracic Radiographs (performed by rDVM): No significant abnormalities.
Skull Radiographs (performed by rDVM): Increased soft tissue opacity within the nasal cavities bilaterally.
Assessment: Bilaterally obstructive nasal disease. Differential diagnoses included non-specific rhinitis (eg. lymphocytic-plasmascytic, suppurative, etc), nasal neoplasia, fungal rhinitis or nasal foreign body.
Recommendations: Nasal CT to be followed by rhinoscopy
Nasal CT was performed before and after intravenous administration of contrast media (Iohexol 240 mgI/ml).
There was fluid accumulation among the left and right nasal turbinates with complete occlusion of airspaces rostrally and only minimal turbinate destruction (Figure 1). A space occupying mass lesion was present in the nasopharynx just caudal to the caudal margin of the hard palate. This lesion had a hyperattenuating (bright) rim in both pre- and post-contrast images and did not demonstrate any significant contrast enhancement. Some contrast of the nasopharyngeal mucosa surrounding this structure was seen. CT findings in the rostral nasal passage were consistent with a non-specific bilateral rhinitis. Differentials for the mass lesion in the nasopharynx included a nasal foreign body, inflammatory polyp or neoplastic mass.
Figure 1. Transverse CT images viewed in bone window from rostral to caudal (A through D). Fluid is present among the nasal turbinates causing nearly complete occlusion of the airspaces within both the left and right nasal passages.
Figure 2. Transverse (A) and sagittal (B) CT images of the head viewed in a soft tissue window. A space occupying mass lesion within the nasopharynx just caudal to the caudal margin of the hard palate. The lesion is shaped like an upside down “witch’s hat” in the transverse image (A) with a hyperattenuating (bright) rim and completely occludes the lumen of the nasopharynx.
Flexible retrograde rhinoscopy was performed and with the endoscope retroflexed dorsally over the soft palate a foreign body was visible within the nasopharynx (Figure 3). A rat tooth grasper instrument was used to grasp the foreign body and retrieve it via the oral cavity. Marked circumferential swelling and bruising of the nasopharyngeal mucosa was noted in the location where the nasal foreign body had been lodged. The lumen of the nasopharynx also appeared significantly narrowed.
The patient was monitored in the hospital overnight and discharged the next day. A tapering dose of prednisone and several days of tramadol for pain were prescribed. Due to the severe nasopharyngeal inflammation and apparently narrowed lumen of the nasopharynx the owners were warned about the possibility of the patient developing a secondary nasopharyngeal stenosis. One week following retrieval of the foreign body the patient was reportedly doing well at home with minimal upper respiratory noise noted.
Figure 3. Retroflexed endoscopic view of the nasopharynx with a nasal foreign body completely occluding the lumen.
Figure 4. The retrieved nasal foreign body was determined to be the cap to an acorn.
A range of diseases can affect the nasopharynx of cats and dogs with neoplasia and inflammatory disease being most common. A variety of neoplasias recognized in the nasal cavity and nasopharynx include lymphosarcoma, carcinomas, mast cell tumor, fibrosarcoma and osteosarcoma. Multiple inflammatory diseases can also be seen including suppurative rhinitis, lymphocytic-plasmacytic rhinitis, inflammatory polyps and fungal rhinitis. While neoplastic masses and inflammatory polyps are the most common cause of nasopharyngeal obstruction, nasal or nasopharyngeal foreign bodies and nasopharyngeal stenosis must also be included on that list.
The most common presenting clinical sign in animals with nasopharyngeal disease is stertor. Repeated attempts at swallowing or “hard-swallowing” may also be noted. Nasal discharge may or may not be present. Sneezing is not typical but may be present with concurrent disease of the nasal turbinates or if the more rostral nasal passages are also involved.
A thorough visual oral and pharyngeal exam under sedation or general anesthesia is warranted in patients tentatively diagnosed with nasopharyngeal disease. The nasopharynx can also be palpated for masses through the soft palate. The use of advanced imaging such as computed tomography (CT) in combination with flexible retrograde rhinoscopy has greatly facilitated the diagnosis of nasopharyngeal disease and therefore the recognition of potentially treatable diseases. CT findings typical of foreign body rhinitis include focal nasal turbinate destruction, hyperplasia of remaining nasal mucosa, and regional accumulation of fluid or mucoid exudates. Changes are typically unilateral unless the nasopharynx is involved rather than the left or right nasal passage. The nasal foreign body itself may or may not be seen depending on both size and composition. Endoscopy additionally allows for treatment of several of these diseases as demonstrated in the above case with endoscopic retrieval of the nasopharyngeal foreign body.
Submitted by: Chris Ryan, VMD, DABVP, DACVR