Cryptococcosis in Cats: Nasal Swelling and Fungal Infection

When sneezing and nasal discharge drag on, and you notice a firm swelling rising over the bridge of your cat's nose, it is time to look deeper. One possible cause is cryptococcosis, a fungal infection that is considered the most common systemic fungal disease in cats. It often starts in the nose, but it can spread to the skin, eyes, lymph nodes and nervous system. This guide explains what cryptococcosis is, where the fungus lives, the signs that warrant a veterinary exam, how veterinarians confirm the diagnosis, what long-term care usually involves, and which signs mean you should contact your veterinarian or an emergency clinic right away.

Important: This article shares general educational information for pet owners and is not a substitute for an in-person veterinary examination, diagnosis, or treatment. For any medical concern or emergency, contact your veterinarian promptly.

What Is Cryptococcosis?

Cryptococcosis is an infection caused by Cryptococcus, a yeast-like fungus. Unlike many fungi that grow as fuzzy strands, Cryptococcus lives as round yeast cells surrounded by a thick, slimy capsule. That capsule helps the fungus dodge the immune system and is also what veterinarians look for under the microscope and in blood tests.

The infection is called "systemic" because it is not limited to the surface of the body. While the nasal cavity is the most frequent starting point in cats, the fungus can travel to nearby tissues, the skin, the eyes, the lymph nodes and, in some cases, the brain and spinal cord.

Where the Fungus Comes From

Cryptococcus lives in soil, decaying plant matter and other organic debris in the environment. Tiny particles can become airborne, and a cat inhales them while sniffing, exploring or simply breathing. Once inside the nose, the fungus can settle in and multiply if the body does not clear it.

Indoor cats are not immune

It is easy to assume that only outdoor cats are at risk, but indoor cats can develop cryptococcosis too. Organic material can be carried in on shoes, clothing and potted plants, and airborne particles can drift through open windows and doors.

Who is more likely to be affected

• Cats of any age: both young adults and older cats can develop it.
• Cats with weakened immunity: an underlying illness can make it harder for the body to keep the fungus in check, although many affected cats have no obvious immune problem.

Nasal Signs: The Most Common Form

In many cats, the first clues involve the nose and upper airway. These changes often develop gradually, which is why they can be mistaken for a stubborn cold at first.

• Persistent sneezing: sneezing that continues for weeks rather than settling down.
• Nasal discharge: discharge from one or both nostrils that may be clear, cloudy, thick or sometimes bloody.
• Noisy breathing: snoring, snorting or a congested sound when breathing through the nose.
• Swelling over the bridge of the nose: a firm, rounded bump that gives the face a so-called "Roman nose" profile.
• A visible mass in a nostril: a fleshy, pinkish growth may protrude from or partly block a nostril.

The swelling over the nose is one of the more distinctive features, but tumors, other infections and polyps can also cause nasal masses or facial swelling. Only testing can tell them apart. If your cat has long-standing sniffles without these other features, our guide to chronic nasal discharge in cats explains other common causes.

Other Forms: Skin, Eyes, Lymph Nodes and Nervous System

Cryptococcosis does not always stay in the nose. Depending on how far it spreads, a cat may show one or several of the following.

Skin

Firm lumps or nodules can appear under or within the skin, especially on the head and face. Some break open and ooze.

Eyes

The infection can affect the inside of the eye. Owners may notice dilated pupils that do not shrink in bright light, cloudiness, redness, a change in eye color or signs of reduced vision such as bumping into furniture. Sudden blindness is an emergency.

Lymph nodes

Lymph nodes under the jaw and in the neck may become enlarged as the immune system responds or as the fungus spreads to them.

Nervous system

When the infection reaches the brain or spinal cord, signs can include seizures, behavior changes, a head tilt, circling, wobbliness, unusual sleepiness or apparent neck pain. Any of these neurologic signs warrant contacting your veterinarian or an emergency clinic right away.

How Veterinarians Diagnose Cryptococcosis

Your veterinarian will begin with a thorough history and physical exam, paying close attention to the nose, face, mouth, eyes, skin and lymph nodes. From there, several tests may be recommended.

1. Cytology: a swab of nasal discharge, a fine-needle sample from a lump or lymph node, or a sample from an open skin lesion is examined under the microscope. The fungus's capsule often makes it recognizable.
2. Latex cryptococcal antigen test: this blood test detects a component of the capsule. It is a key tool both for diagnosis and for tracking progress later.
3. Biopsy: a small tissue sample, usually taken under sedation or anesthesia, can confirm the diagnosis and rule out tumors or other diseases.
4. Imaging: X-rays, CT or MRI may be used to assess the nasal cavity, the chest and, when neurologic signs are present, the brain.
5. Bloodwork and urinalysis: these check overall health, organ function and suitability for long-term medication.

Your veterinarian will also commonly recommend testing for feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV), because these infections can affect immune function and influence the overall plan. Our article on FeLV and FIV in cats explains what these tests mean.

What Care and Management Usually Involve

Many cats respond well when cryptococcosis is caught early and managed consistently. The plan depends on which parts of the body are involved.

Long-term antifungal medication

The cornerstone of management is oral antifungal medication, given as prescribed by your veterinarian. Courses are typically long, often lasting several months or longer, because fungal infections clear slowly.

Antigen rechecks guide the timeline

Your veterinarian will usually repeat the cryptococcal antigen blood test at intervals. A falling result suggests the infection is coming under control, and these results help your veterinarian decide when it may be appropriate to end medication.

Surgery and supportive care

In some cases, a large nasal mass or skin nodule may be surgically removed or reduced to improve breathing or comfort, alongside medication. Cats that are not eating well may need fluids or appetite support, and periodic bloodwork helps your veterinarian watch for medication side effects. The outlook is generally better when the nervous system is not involved.

Supporting Your Cat at Home

Home care works alongside your veterinarian's plan and never replaces it.

If your cat develops a nosebleed rather than ordinary discharge, our guide to nosebleeds in dogs and cats covers what to do while you contact your veterinary team.

When to Call Your Veterinarian

Long-lasting nasal signs or a new swelling on the face warrant a veterinary exam. Schedule an appointment soon if your cat has:

• Sneezing or nasal discharge that has not improved over a couple of weeks
• Discharge from only one nostril, or discharge that is thick or occasionally tinged with blood
• A firm swelling over the bridge of the nose or a change in the shape of the face
• A visible growth in or around a nostril
• New lumps or nodules in the skin, especially on the head
• Enlarged lymph nodes under the jaw
• Cloudiness, redness or a change in color in one or both eyes, without any change in vision

Contact your veterinarian or an emergency clinic right away if your cat

• Has a seizure
• Has difficulty breathing, breathes with an open mouth or struggles to move air
• Suddenly seems blind or starts bumping into things
• Shows sudden behavior changes, a new head tilt, circling, wobbliness, severe sleepiness or apparent neck pain
• Has heavy or ongoing nasal bleeding
• Refuses all food or becomes weak and withdrawn
• Develops yellowing of the gums, skin or whites of the eyes

If your cat has a seizure, keep hands away from the mouth, move objects that could cause injury and note how long it lasts. Our guide to seizures in dogs and cats explains what to do while you get help.

Common Myths and Mistakes

Myth: My cat lives indoors, so it cannot be a fungal infection.

Fact: indoor cats can be affected. The fungus lives in organic debris in the environment, and airborne particles can reach cats inside the home.

Mistake: Dismissing long-term sneezing as just a cold.

Fact: many upper respiratory infections settle on their own, but sneezing and discharge that persist, or that come with facial swelling or a nostril mass, deserve a proper workup.

Myth: Once the swelling goes down, the infection is gone.

Fact: visible signs often improve well before the infection is fully under control. Antigen rechecks help your veterinarian judge when medication can safely end.

Mistake: Skipping doses or ending medication early.

Fact: gaps in medication give the fungus a chance to regain ground.

Myth: A cat with cryptococcosis is dangerous to the family.

Fact: the infection is not considered to spread from cats to people through casual contact. People and pets usually acquire it from the same environment rather than from each other.

Frequently Asked Questions

Is cryptococcosis contagious to other cats or dogs in my home?

It is not generally considered to spread from one pet to another through normal contact. However, pets sharing the same environment may share the same exposure, so mention any similar signs in your other pets to your veterinarian.

Can I catch cryptococcosis from my cat?

It is not considered to spread from cats to people through casual contact. People with weakened immune systems who have health concerns should speak with their own physician.

How long will my cat need medication?

Courses commonly last many months. Your veterinarian will use exam findings and repeat antigen tests to decide when it is appropriate to end medication.

Will the bump on my cat's nose go away?

In many cats, the swelling shrinks substantially as the infection comes under control, although some cats keep a slight change in facial shape.

Key Takeaways

Cryptococcosis is the most common systemic fungal infection of cats. The fungus lives in soil, decaying plant matter and other organic debris in the environment, and indoor cats can be affected as well as outdoor cats. The nasal form is most common and can cause persistent sneezing, nasal discharge that is sometimes bloody, a firm "Roman nose" swelling and masses in a nostril. Skin nodules, eye changes, enlarged lymph nodes and neurologic signs can also occur. Diagnosis usually involves cytology, a latex cryptococcal antigen test, biopsy and imaging, plus FeLV and FIV testing. Management typically means months of oral antifungal medication as prescribed by your veterinarian, with antigen rechecks to guide how long it continues. The outlook is better when the nervous system is not involved. Contact your veterinarian or an emergency clinic right away for seizures, difficulty breathing, sudden blindness or other sudden neurologic changes.