Rabbits in the U.S. are developing bizarre, tentacle-like growths on their heads—and experts say a rare fungal infection is to blame. Videos of the affected animals, primarily in Texas and Florida, have gone viral, raising questions about whether the condition is contagious, treatable, or even dangerous to humans. According to the Centers for Disease Control and Prevention (CDC) and veterinary pathologists, the growths are caused by Conidiobolus coronatus, a fungus that thrives in warm, humid environments and can infect rabbits, dogs, and occasionally humans. While cases remain rare, the sudden surge in reports has prompted pet owners and veterinarians to take notice.
The fungal infection, known as entomophthoromycosis in rabbits, typically manifests as rapidly enlarging, gelatinous masses around the face, ears, or nose. Unlike tumors or cancers, these growths are not malignant but can be disfiguring and life-threatening if untreated. The CDC has not issued a formal alert, but state veterinary authorities in Texas and Florida confirm they are investigating clusters of cases. “We’ve seen a noticeable increase in rabbits presenting with these symptoms over the past six months,” said Dr. Elena Martinez, a veterinary dermatologist at the Texas Veterinary Medical Association. “The growths can obstruct breathing and lead to secondary infections if not addressed promptly.”
Why are these cases appearing now? Experts point to a combination of factors: rising temperatures, increased outdoor rabbit populations, and potential environmental changes due to climate shifts. Conidiobolus coronatus spores are commonly found in soil, decaying plant matter, and insect habitats. Rabbits—especially those kept in outdoor enclosures or free-roaming—are at higher risk of exposure. “The fungus is opportunistic,” explained Dr. Richard Chen, a mycologist at the U.S. Food and Drug Administration’s Center for Veterinary Medicine. “When rabbits are stressed, immunocompromised, or live in damp conditions, their risk of infection spikes.” Recent heatwaves in the Southern U.S. may have created ideal conditions for spore proliferation.
Note: The video above shows a rabbit with facial growths consistent with Conidiobolus coronatus infection. For ethical reasons, the animal’s identity and location have been obscured.
What Is Conidiobolus coronatus and How Does It Infect Rabbits?
Conidiobolus coronatus is a type of entomophthoralean fungus, a group typically found in tropical and subtropical regions. While it rarely affects humans, it can cause severe infections in small mammals, particularly rabbits. The fungus enters the body through the respiratory tract or broken skin, then spreads to subcutaneous tissues, where it forms the characteristic gelatinous masses. “The growths start small but can double in size within days,” said Dr. Martinez. “They’re not painful at first, but as they expand, they can cause breathing difficulties, eye infections, or even systemic illness if the fungus enters the bloodstream.”
Diagnosis requires a biopsy or fungal culture, which is not always readily available. Veterinarians often rely on clinical signs—such as rapid growth, lack of pain, and the gelatinous texture—to suspect the infection. Treatment typically involves surgical removal of the growths combined with antifungal medications, including itraconazole or terbinafine. However, recurrence is common if spores remain in the environment. “Owners must disinfect cages thoroughly and monitor their rabbits for regrowth,” warned Dr. Chen.
Is This Infection Contagious to Humans or Other Pets?
While Conidiobolus coronatus is not considered highly contagious, the CDC notes that immunocompromised individuals—such as those with HIV, chemotherapy patients, or organ transplant recipients—may be at risk of infection if exposed to large numbers of spores. “There’s no evidence this is spreading like a virus,” said Dr. Martinez. “But pet owners should practice good hygiene—washing hands after handling rabbits, cleaning enclosures regularly, and avoiding contact with soil or decaying organic matter where the rabbit roams.”
Dogs and cats can also contract fungal infections, though Conidiobolus coronatus is less common in these species. The American Veterinary Medical Association (AVMA) advises pet owners to isolate infected animals temporarily to prevent environmental contamination. “If you notice unusual growths on your pet, consult a vet immediately,” said Dr. Chen. “Early treatment improves outcomes significantly.”
Where Are Cases Concentrated—and What’s Being Done?
Most confirmed cases have been reported in Texas, Florida, and parts of the Southeast U.S., where humidity and warm temperatures favor fungal growth. The Texas Department of Agriculture has received reports of at least 12 cases in domestic rabbits since January 2024, though the true number may be higher given underreporting. Florida’s Division of Animal Industry is also tracking cases but has not released exact figures.
Neither state has issued a public health advisory, but veterinarians recommend the following precautions for rabbit owners:
- Keep rabbits indoors or in well-ventilated, dry enclosures.
- Avoid letting rabbits dig in soil or forage near decaying plant matter.
- Monitor for sudden facial swelling or gelatinous growths.
- Disinfect cages monthly with a 10% bleach solution.
- Consult a vet if symptoms appear—do not attempt home remedies.
The CDC states that there is no evidence this is an emerging epidemic, but the agency is monitoring reports. “We’re not seeing human cases linked to these pets,” said a CDC spokesperson. “But we encourage vigilance, especially in areas with high rabbit populations.”
What Happens Next? Monitoring and Research
Veterinary researchers are investigating whether climate change or agricultural practices—such as increased use of fungicides—are contributing to the rise in cases. The National Institute of Allergy and Infectious Diseases (NIAID) has funded studies on fungal zoonoses, though none specifically target Conidiobolus coronatus in rabbits. “This isn’t a new pathogen, but the conditions for its spread may be changing,” said Dr. Chen.
For now, pet owners are advised to stay alert. The ASPCA recommends reporting suspicious cases to local veterinary authorities to help track trends. “The key is early detection,” said Dr. Martinez. “These growths might look alarming, but with prompt treatment, many rabbits recover fully.”
Key Takeaways: What Rabbit Owners Need to Know
- Symptoms: Gelatinous, rapid-growing masses on the face, ears, or nose—often painless at first.
- Cause: Conidiobolus coronatus, a fungus found in soil and decaying organic matter.
- Risk: Low to humans unless immunocompromised; higher for rabbits in warm, humid climates.
- Treatment: Surgical removal + antifungal medication (itraconazole/terbinafine).
- Prevention: Keep rabbits indoors, disinfect enclosures, and avoid contact with contaminated soil.
- Next Steps: Report cases to local veterinary authorities; monitor for recurrence.
If you suspect your rabbit has this infection, find a veterinarian near you for diagnosis. For updates on fungal diseases in pets, follow the CDC’s fungal disease resources or the AVMA’s pet health alerts.
Have you encountered rabbits with similar symptoms? Share your experiences in the comments—or help spread awareness by sharing this article. For official updates, check back for further developments as investigations continue.