Deadly Fungal Disease in Cats Spreading Fast Across Borders

A cat-linked fungus that can kill animals and infect people is pushing beyond Brazil, and veterinarians are warning the map may keep changing.

Quick Take

The fungus is called Sporothrix brasiliensis, and it causes cat-transmitted sporotrichosis.
Reporting shows it has spread from Brazil into neighboring South American countries.
The disease can be severe in cats and can also infect people and dogs.
The Centers for Disease Control and Prevention says the threat may spread outside South America.

A Brazilian Outbreak With Teeth

Sporothrix brasiliensis started as a Brazilian problem and grew into a regional one. Science News reported that it has sickened and killed thousands of cats and infected more than 11,000 people and at least 200 dogs in South America since the 1990s, with spread now documented in Paraguay, Chile, Argentina, and Uruguay. That scale matters because this is not a slow, hidden fungus. It moves through cats, then through the people who handle them.

The disease has also crossed a line that makes public health officials sit up. The Centers for Disease Control and Prevention says Sporothrix brasiliensis causes an emerging disease that spreads from cats to people and may spread outside South America. The American Veterinary Medical Association also reported that the Centers for Disease Control and Prevention warned about the potential for spread to the United States.

Why Cats Sit at the Center

Cats are not just victims in this story. They are the main engine of spread. Health guidance and research say infected cats can pass the fungus through bites, scratches, and contact with lesions, and cats can carry heavy fungal loads. That is why this outbreak has moved so fast in places where stray and domestic cats mix. A single sick animal can seed a household, a clinic, or a neighborhood before anyone knows what they are facing.

Reporting from the United Kingdom added another layer. Researchers described the first three cases of cat-transmitted sporotrichosis caused by Sporothrix brasiliensis outside South America, showing the fungus can travel farther than the original South American hotspot. That does not mean the disease has become common worldwide. It does mean the organism is no longer trapped in one country, one city, or one easy-to-ignore corner of the map.

How Fast the Disease Has Moved

The speed of expansion is part of what makes this outbreak unusual. CDC-linked reporting says cases in Brazil have been found across much of the country, and neighboring South American countries have documented infections as well. In Chile, researchers recently found Sporothrix brasiliensis in cats in Santiago, reinforcing the view that the fungus is actively expanding across the continent.

A highly transmissible fungus carried by cats is spreading rapidly across South America and may eventually reach the United States.

Sporothrix brasiliensis is fueling a large outbreak of sporotrichosis among cats in Brazil and neighboring countries. The disease can cause painful… pic.twitter.com/CmahykvxMK

— Massimo (@Rainmaker1973) August 6, 2026

That spread is especially troubling because fungal outbreaks often advance quietly. People may mistake the first sores for ordinary skin infections, and sick cats may stay at home long enough to infect more animals and owners. The disease can cause painful lesions, and reporting says it can be fatal in cats and sometimes in humans too. That makes early recognition more than a veterinary issue. It becomes a family safety issue.

Why Public Health Officials Are Watching Closely

This outbreak fits a familiar pattern in emerging infections: an animal disease grows, surveillance lags, and the problem crosses borders before most people notice. The public record here shows a fungal pathogen that has already built a large foothold in Brazil and then pushed into nearby countries, with isolated cases beyond the region. That is why the warnings have sharpened. The question is no longer whether the fungus exists. It is how far it can go next.

For cat owners, the practical lesson is plain. Sick cats with skin sores, swollen nodes, or unexplained wounds need veterinary care, not guesswork. People who handle stray cats, rescue animals, or work in clinics face the highest exposure risk. The best response is simple: treat strange skin disease in cats as serious, limit rough contact, and get prompt testing when lesions do not heal. In an outbreak like this, delay is how a local problem becomes a wider one.