cryptococcosis
Expert veterinary guidance.
Cryptococcosis is a fungal infection caused by Cryptococcus neoformans or C. gattii, and is the most common systemic fungal disease affecting cats worldwide. The fungus is found in pigeon droppings, soil, and decaying wood. Cats typically become infected by inhaling fungal spores, leading to nasal, skin, pulmonary, or neurological disease. Early recognition and treatment are important for a good outcome. Source: Clinician's Brief, 2025.
- Cryptococcosis is the most common systemic fungal infection in cats, found worldwide
- Infection occurs through inhalation of fungal spores — pigeon droppings are a major reservoir
- The most common form affects the nose — causing nasal discharge, sneezing, and nasal swelling
- Skin lesions (nodules, ulcers) are the second most common presentation
- Diagnosis involves blood antigen testing (latex agglutination) and/or tissue biopsy
- Treatment requires long-term antifungal medication (itraconazole, fluconazole) for 2-6+ months
How Cats Get Infected
Cryptococcus fungi thrive in pigeon droppings, soil enriched with bird waste, and decaying organic matter. Cats become infected by inhaling spores from contaminated environments. Indoor cats can still be exposed through open windows or on shoes/clothing. The fungus primarily affects the nasal passages first, then can spread to the skin, lungs, eyes, and central nervous system. Immunosuppressed cats (e.g., FIV-positive) are at higher risk.
Forms and Symptoms
Nasal form (most common): chronic nasal discharge (clear, mucoid, or bloody), sneezing, nasal swelling or deformation, and difficulty breathing. Skin form: firm nodules, ulcers, or non-healing wounds, especially on the head and neck. Pulmonary form: coughing, difficulty breathing. Neurological form: seizures, circling, head tilt, paralysis — this is the most serious form with a guarded prognosis.
Diagnosis and Treatment
Diagnosis involves: nasal swabs or tissue biopsies with special staining, blood or urine antigen testing (latex agglutination — very sensitive and specific), and sometimes imaging (X-rays, CT scan). Treatment requires long-term oral antifungal medication: itraconazole (most common, 5-10 mg/kg daily) or fluconazole (5-10 mg/kg daily). Treatment typically lasts 2-6 months, continued until antigen tests are negative. Severe or neurological cases may require initial IV antifungal treatment (amphotericin B).
Prognosis
The prognosis for localized nasal and skin cryptococcosis is good with proper treatment — most cats recover fully. The prognosis for pulmonary disease is fair. Neurological cryptococcosis has a more guarded prognosis due to difficulty achieving adequate drug concentrations in the brain. Early diagnosis and treatment significantly improve outcomes. Relapse can occur, so follow-up antigen testing is recommended after treatment completion.
- Your cat has persistent nasal discharge that doesn't respond to antibiotics
- Your cat has unexplained skin nodules or non-healing wounds on the head or neck
- Your cat's nose appears swollen or deformed
- Your cat has chronic sneezing with or without nosebleeds
- Your cat shows neurological symptoms — seizures, circling, or loss of balance
- Your outdoor cat is exposed to pigeon droppings or environments with bird waste
RVC
Royal Veterinary Center can diagnose and treat cryptococcosis in cats. We offer in-house diagnostic testing including fungal culture, special staining, and can coordinate blood antigen testing. Our exotic animal team has experience managing long-term antifungal therapy and monitoring treatment response. Early diagnosis leads to better outcomes — don't delay if your cat shows unexplained nasal or skin symptoms. Call +853 6677 6611.
+853 6677 6611