Abstract
Clinical report
A 5-year-old male neutered domestic medium-haired indoor cat presented to a private specialty hospital for evaluation of respiratory difficulties of 3 days' duration. The cat had acutely developed a wet cough and blood-tinged mucoid nasal discharge.
History
The cat had a dry cough, episodes of which occurred every 3–4 weeks. Three days prior to being seen by the authors, he was evaluated at an emergency clinic and had normal vital signs (including a respiratory rate of 24–30 breaths per min) with a mild increase in respiratory effort and a moderate increase in upper and lower airway sounds. Cardiac auscultation revealed no abnormalities and there was no nasal discharge. Lateral and ventrodorsal thoracic radiographs showed a moderate bronchial pattern and the stomach was gas dilated. The patient received 6.8 mg (1 mg/kg) of dexamethasone sodium phosphate intravenously and was discharged with 5 mg prednisone tablets to be given orally one tablet once daily for 3 days.
Two days later the cat presented to the emergency hospital for open-mouth breathing and purulent nasal discharge. On presentation the vital signs were normal (respiratory rate 36 breaths per min). However, the cat had labored inspiration with a moist gurgling sound heard over the trachea. The patient was hospitalized, placed in an oxygen cage, and treated with 6 mg of dexamethasone sodium phosphate and 24 mg (3.8 mg/kg) of amino-phylline, both given intravenously.
Physical examination and preliminary investigations
The following day the cat presented to the specialty hospital. Physical examination revealed a mucopurulent discharge from the cat's right nostril and mild bilateral conjunctivitis. He gagged frequently, and showed intermittent open-mouth breathing. Auscultation of the lungs revealed no abnormalities; however, referred upper airway sounds were heard on inspiration and expiration.
Initial diagnostic tests included routine hematology and serum biochemistry, lateral and ventrodorsal thoracic radiography, and lateral cervical radiography. Abnormalities noted included hyperglycemia (252 mg/dl; reference interval [RI] 64–170 mg/dl), thrombocytosis (587 × 10 3 /μl; RI 200–500 × 10 3 /μl), neutrophilia (13.2 × 10 3 /μl; RI 2.5–8.5 × 10 3 /μl), monocytosis (1.0 × 10 3 /μl; RI 0.0–0.6 × 10 3 /μl) and lymphopenia (0.4 × 10 3 /μl; RI 1.2–8.0 × 10 3 /μl). These changes were all attributed to stress. A heartworm antibody test, and feline leukemia virus and feline immunodeficiency virus tests were negative. Thoracic radiographs revealed a moderate diffuse bronchial pattern with a mild diffuse interstitial pattern. The caudal thoracic esophagus contained a small amount of fluid and the stomach was moderately gas dilated. The lateral cervical radiograph (Fig 1) showed a soft tissue opacity mass filling the caudal aspect of the nasopharynx. The portion of the nasopharynx caudal to the mass and the laryngopharynx were moderately gas filled.
Lateral cervical radiograph showing a soft tissue opacity within the caudal aspect of the nasopharynx and moderate dilation of the oropharynx
Nasopharyngeal examination
The thoracic radiographs were suggestive of feline asthma. However, the nasopharyngeal mass was felt to be the likely source of the cat's respiratory signs and a nasopharyngeal examination was performed under anesthesia. The cat was anesthetized with 23 mg (4 mg/kg) of propofol intravenously, intubated and maintained on isoflurane. On examination of the oropharynx a large pedunculated and mucus-covered mass was seen, extending from above the soft palate and occupying approximately 80% of the oropharynx. Mosquito hemostats were used to grasp the mass in order to visualize it better for biopsy. In the process, the mass began to disintegrate and small chunks of mucus and hair were removed. The mass was then dislodged, at which point it became clear that it was a trichobezoar. The oropharynx was packed with gauze prior to a thorough nasal lavage with saline. The patient recovered uneventfully from anesthesia.
The cat was discharged with oral amoxicillin-clavulanate (Clavamox; Pfizer), oral meloxicam (Metacam; Boehringer Ingelheim) and saline drops for the nose. The patient returned 1 week later for a recheck examination and to address the historical coughing and possible asthma after full recovery from the foreign body removal. The owner reported that the cat had returned to normal and had experienced only mild nasal discharge.
Recurrence
Approximately 1 year later, the cat presented with gagging and intermittent open-mouth breathing of 4 h duration following an episode of vomiting. The owner reported that the cat had been vomiting trichobezoars two to three times weekly. A lateral cervical radiograph was unremarkable. However, on endoscopic nasopharyngeal examination under anesthesia a trichobezoar was found lodged immediately caudal to the choanal openings (Figs 2 and 3).
Endoscopic view of the nasopharynx showing the trichobezoar prior to removal
Endoscopic view of the nasopharynx following removal of the trichobezoar; note the secondary erythema of the nasopharyngeal mucosa
Alligator forceps were threaded through the endoscope to retrieve the trichobezoar (Fig 4). A 0.2 mg/kg dose of dexamethasone sodium phosphate was administered intravenously and the cat was discharged from the hospital with a recommendation for endoscopy of the gastrointestinal tract with biopsies to evaluate any underlying causes that might be leading to the frequent vomiting and/or development of hair balls.
The owner did not, however, return for evaluation and management of the chronic vomiting.
The second trichobezoar following removal
Discussion
Clinical signs of nasopharyngeal disease include stertor, open-mouth breathing, repeated attempts at swallowing and pawing at the nose. Animals with foreign bodies within the nasopharynx can develop halitosis and nasal discharge. 1 Nasopharyngeal disease can be caused by infectious, inflammatory, neoplastic or anatomic abnormalities, and foreign bodies. Infectious causes include bacterial, viral and fungal etiologies. Cats with chronic bacterial rhinitis can develop secondary nasopharyngitis due to exposure of the nasopharynx to draining infected secretions. 2 Although Cryptococcus neoformans more commonly causes rostral rhinitis, primary fungal granulomas can be found in the nasopharynx, leading to upper airway obstruction. 3 Aspergillus species has also been reported to cause signs of nasopharyngeal disease in the cat. 4 Anatomic abnormalities such as nasopharyngeal stenosis can be caused by chronic infection or trauma to the nasopharynx and are typically managed surgically or with balloon dilation. 5
Based on the nasopharyngeal mass noted on the lateral cervical radiograph, nasopharyngeal neoplasia was the most likely differential, although a nasopharyngeal polyp was also a consideration. Neoplasia is more common in middle-aged to older cats, but can occur at any age. The most common tumors affecting the feline nasopharynx include lymphosarcoma, adenocarcinoma and squamous cell carcinoma. 6,7 Nasopharyngeal polyps are a common cause of nasopharyngeal disease in young cats but have been reported in cats as old as 15 years of age. 8 Polyps appear as pedunculated masses and are composed of inflammatory tissue covered in respiratory epithelium, and can be visualized during an anesthetized nasopharyngeal examination. Computed tomography scans and nasal biopsies are optimal for diagnosis of nasal tumors. Squash cytology of biopsy samples may be adequate for obtaining a diagnosis from nasopharyngeal masses that are easily visualized using flexible endoscopic techniques. 9,10
Nasopharyngeal foreign bodies can result from ingestion of the foreign body, vomition or regurgitation of the material, or direct introduction through the nose. Commonly reported foreign bodies in the feline nasopharynx include grass awns and sewing needles. Foreign bodies cause an acute onset of clinical signs, which may worsen slightly with time as inflammation develops. Depending on the opacity of the foreign material, skull radiographs may be used to identify foreign material within the nasopharynx. In the case reported here, due to the location and opacity of the initial trichobezoar, the foreign body was readily seen on a lateral projection of the neck. It was, however, suspected to be a soft tissue mass. On the second presentation the trichobezoar was not identified radiographically. To the authors' knowledge this is the first reported case of a nasopharyngeal trichobezoar foreign body.
Frequent vomition of trichobezoars is considered a manifestation of underlying gastrointestinal pathology, or dermatologic, neurologic or behavioral disease. Large studies evaluating common conditions leading to trichobezoar formation are lacking. Long hair, flea-allergic dermatitis, inflammatory bowel disease and ingestion of plant material were cited as predisposing causes in a small series of cats with intestinal trichobezoars. 11 Unfortunately, the cat in this study was lost to follow-up prior to evaluation or treatment of the cause of the frequent hair balls.
In conclusion, an important first step in the assessment of cats with respiratory signs is distinguishing between upper and lower respiratory disease. Nasopharyngeal disease can be caused by myriad infectious, inflammatory and neoplastic etiologies. However, simpler causes such as foreign bodies can be considered in cases of acute-onset nasopharyngeal disease.