CDC Links Human-to-Cat Transmission of Bird Flu

A new study published in the Morbidity and Mortality Weekly Report by the U.S. Centers for Disease Control and Prevention (CDC) suggests that household cats can contract deadly bird flu (H5N1) from infected humans.

Two Michigan cases in May 2024 documented fatal bird flu infections in domestic cats living with dairy farmworkers. This finding raises urgent concerns about viral mutation and pandemic risks as avian influenza continues to spread among birds and mammals.

Case 1: Cat Develops Neurological Symptoms & Dies

Symptoms & Progression:

•  5-year-old indoor cat developed loss of appetite, disorientation, and neurological decline
• Required emergency veterinary care but euthanized within four days
• Postmortem confirmed H5N1 bird-flu infection

Household Exposure:

• Lived with two other cats (one had mild symptoms)
• Owner worked on an H5N1-affected dairy farm
• Owner refused bird flu testing, while family members tested negative

Case 2: Raw Milk Exposure & Rapid Death

Symptoms & Exposure:

• 6-month-old Maine Coon showed anorexia, lethargy, and facial swelling
• Died within 24 hours of symptom onset
• Owner transported unpasteurized milk from infected dairy farms
• Frequently handled raw milk without protective gear
• Sick cats often rolled in contaminated work clothes

Key Takeaways: How Bird Flu Spreads to Cats

Possible transmission routes:

• Contact with infected dairy farmworkers
• Exposure to contaminated clothing and surfaces
• Consumption of raw milk from infected cattle

Public Health Risks: Could Bird Flu Mutate?

Experts fear that continued virus circulation among mammals could lead to a strain capable of human-to-human transmission.

Current Stats in the U.S.:

• 69 confirmed human cases since 2024 (likely underreported)
• One human death recorded
• Cats, big cats, and cattle now infected

CDC advises farm workers to change clothes and wash thoroughly before entering homes to reduce transmission risks.

Conclusion: A Growing Zoonotic Threat

This study highlights the urgent need for stricter biosecurity measures to prevent further spillover from animals to humans. As bird flu spreads across species, rapid surveillance, protective measures, and vaccination strategies could be crucial in preventing a future pandemic.

More Information: Ramya Naraharisetti et al, Highly Pathogenic Avian Influenza A(H5N1) Virus Infection of Indoor Domestic Cats Within Dairy Industry Worker Households — Michigan, May 2024, MMWR. Morbidity and Mortality Weekly Report (2025). DOI: 10.15585/mmwr.mm7405a2