Missy, a 2-year-old spayed domestic medium haired cat, is presented for chronic nasal congestion and stertor. What are your top 3 differential diagnoses?

• A. Nasopharyngeal polyp, chronic rhinitis, nasal neoplasia
• B. Nasopharyngeal polyp, chronic rhinitis
• C. Chronic rhinitis, nasal neoplasia
• D. Nasopharyngeal polyp, chronic rhinitis, cryptococcosis

Answer: (A)

When a young cat presents with chronic nasal congestion and stertor, the most likely causes are nasopharyngeal polyp, chronic rhinitis, and nasal neoplasia. Nasopharyngeal polyps are common in young cats and arise from the nasopharynx or middle ear, protruding into the nasal passages to cause obstruction and stertor. Chronic rhinitis is another frequent culprit, reflecting persistent inflammatory changes of the nasal mucosa from infection or irritation, which can produce ongoing obstruction and discharge that leads to stertor. Nasal neoplasia, while more common in older cats, still should be on the list because tumors such as lymphoma or carcinomas can cause unilateral or bilateral obstruction and nasal discharge; imaging and biopsy are needed for confirmation. Cryptococcosis can cause nasal signs but is less likely as a top three differential in a 2-year-old without other suggestive signs, so it’s typically considered after the above more likely etiologies.