Stay Informed: This Blog is Continuously Updated
This blog will be regularly updated with new developments, including reports of H5N1 cases in cats and dogs, the newest research findings, and expert advice for pet owners.
February 2025
What is H5N1?
We’ve all heard of bird flu, but lately, it seems to be making headlines more and more. H5N1, a type of highly pathogenic avian influenza, is causing outbreaks in wild birds and poultry worldwide, and it’s even been detected in some mammals, including cats and dogs. This has many pet owners understandably concerned. In this blog, we will highlight the general concerns about H5N1 and the risks to your furry family members.
H5N1 is a highly pathogenic avian influenza, causing outbreaks in wild birds and poultry worldwide
Key traits of H5N1
- Highly pathogenic: It causes severe illness and high mortality rates in birds, especially poultry.
- Can infect mammals: While birds are the primary hosts, H5N1 can infect various mammals, including cows, pigs, cats, and dogs.
- Rare human infections: Human infections are relatively uncommon but can be severe, leading to pneumonia, respiratory failure, and even death.
- Pandemic potential: There is concern that the virus could mutate and become easily transmissible between humans, potentially causing a pandemic
H5N1 isn’t New… How in the world Did We Get Here?
H5N1 was first discovered in 1996 in geese in China. Since then there have been increasing reports of infections in additional countries and species of animals. Here’s a timeline:- 1997: The first human cases of H5N1 were identified in Hong Kong.
- 2003-2019: H5N1 outbreaks occurred in poultry and wild birds in Asia, Africa, Europe, and the Middle East, with sporadic human cases.
- 2020: A new wave of H5N1 emerged, causing significant outbreaks in birds globally.
- 2021: H5N1 spread to North America.
- 2022: The first human case of this new wave of H5N1 was detected in the US.
- 2023: H5N1 outbreaks in mammals, including mink, foxes, and seals, raised concerns about increased mammal-to-mammal transmission.
- 2024: H5N1 was detected in US dairy cows and cats, marking a significant jump to a new mammalian host.
- Early 2025:
- H5N1 positive dairy cattle have been reported in 17 states, with Arizona being the most recent state. (Source: Arizona Department of Agriculture).
- In the United States, there have been 70 confirmed human cases of H5N1 since 2024, with one death reported in Louisiana. (Source: CIDRAP).
- A Wyoming woman is confirmed infected and hospitalized. (Source: Wyoming Department of Health).
- For the first time, H5N1 was found in rats in Riverside, CA. (Source: USDA)
Where Have Pets Been Infected with H5N1?
A comprehensive list of global dog and cat infections is difficult to compile due to inconsistent and incomplete reporting, however, there have been some prominent reports in the news including:
Cats:
- United States:
- Oregon (2024-2025): Multiple cases, mainly linked to contaminated raw pet food or hunting behavior. Many cats displayed neurological symptoms (seizures, tremors, paralysis) and, sadly, were euthanized due to the severity of their illness. (Source: Oregon Veterinary Medical Association)
- California (2024): Cases linked to both raw pet food and unpasteurized milk consumption, prompting public health warnings. (Source: Los Angeles County Department of Public Health)
- South Korea (2023): Outbreak in two Seoul cat shelters traced to improperly sterilized raw duck meat used in pet food, highlighting the risk of contaminated food. (Source: Emerging Infectious Diseases journal)
- Poland (2023): A large outbreak in cats across the country, with various potential sources of infection under investigation. (Source: World Organisation for Animal Health (WOAH))
- Outcomes: In many reported cases, cats experienced severe illness, including neurological and respiratory symptoms, often leading to euthanasia or death.
Dogs:
- Lower Susceptibility: Dogs seem less susceptible to H5N1 and typically experience milder symptoms.
A comprehensive list of global dog and cat infections is difficult to compile due to inconsistent and incomplete reporting
How Are Cats Getting Infected with H5N1?
Cats have become infected with H5N1 through various routes, primarily involving contact with infected birds or contaminated, often raw, food.
Consumption of Infected Birds:
- Natural Hunting Behavior: Cats are natural predators and often hunt birds. If they catch and eat a bird infected with H5N1, they can become infected. This is a concern for outdoor cats, especially in areas with high prevalence of H5N1 in wild bird populations.
- In January 2025, an outdoor cat in Washington County, Oregon, tested positive for H5N1. The cat had a history of exposure to wild waterfowl, which were likely the source of infection. (Source: Oregon Veterinary Medical Association)
Contaminated Raw Meat and Pet Food:
- Raw Pet Food: Feeding cats raw pet food, especially if it contains poultry or has not been properly handled and stored, can expose them to H5N1. Several outbreaks in cats have been linked to contaminated raw pet food.
- In February 2025, two cats in Multnomah County, Oregon, were euthanized after consuming the same brand of raw pet food contaminated with H5N1. (Source: Oregon Veterinary Medical Association)
- In December 2024, a cat in Washington County, Oregon, died after eating contaminated raw pet food. (Source: US Food and Drug Administration)
- In December 2024, multiple cats in Los Angeles County, California, tested positive for H5N1 after consuming raw pet food. (Source: Los Angeles County Department of Public Health)
Unpasteurized Milk:
- Raw Milk: Cats can also become infected by drinking unpasteurized milk from infected cows. This was a concern during the outbreak of H5N1 in dairy cows in the US in 2024.
- In December 2024, several cats in Los Angeles County, California, became ill and died after consuming recalled raw milk contaminated with H5N1. (Source: Los Angeles County Department of Public Health)
Horizontal and Zoonotic Transmission:
- Horizontal transmission (cat-to-cat), and zoonotic transmission (cat-to-human) of H5N1 is not yet reported. Regardless, ongoing research and surveillance for this concerning possibility continues.
What Are the Symptoms of H5N1 in Cats
Neurological issues: Neurological signs are more commonly reported in cats and can be quite severe.
Symptom variation: The severity and range of symptoms can vary between individual animals. Other symptoms could include respiratory issues, general malaise, fever and poor appetite.
Rapid progression: In cats, the disease can progress rapidly, and severe symptoms leading to death can develop quickly.
Testing Cats for Bird Flu: The PCR Test
Diagnosing H5N1 in cats typically involves a polymerase chain reaction (PCR) test, which your veterinarian will submit — there is no approved at-home testing. This test detects the virus’s genetic material in samples like swabs from the nose and throat, blood, or urine. Your veterinarian will need to coordinate the testing process, which is usually conducted at a lab within the National Animal Health Laboratory Network (NAHLN).
Why is testing important? Early detection of H5N1 allows for prompt treatment and helps prevent the spread of the virus to other animals, including humans. If you suspect your cat might have bird flu, contact your veterinarian for guidance.
How is H5N1 Treated in Cats?
Supportive care: This is currently the mainstay of treatment for cats with H5N1, aiming to manage symptoms and complications, while providing the patient time for its own immune system to mount a response to fight the infection:
- Hospitalization: Cats with severe illness often require hospitalization for intensive care.
- Fluid therapy: Intravenous fluids to maintain hydration and electrolyte balance.
- Oxygen therapy: If respiratory distress is present.
- Nutritional support: May be necessary if the cat is not eating adequately. The placement of a temporary feeding tube to provide nourishment to cats who won’t eat can be helpful.
- Antibiotics: To treat secondary bacterial infections that may occur. It is important to remember that antibiotics are not effective against H5N1.
- Nursing care: Careful monitoring and supportive nursing care to manage symptoms and ensure comfort.
Antiviral Medications: While recommended for the use of H5N1 infection in people, the effectiveness of Tamiflu (oseltamivir) in the treatment of bird flu infections in dogs and cats is unclear and further investigation is needed.
How to Protect Your Pet from Becoming Infected with H5N1
Limit Exposure to Birds:
- Keep cats indoors: Prevent cats from hunting and interacting with wild birds, which are the primary carriers of H5N1.
- Supervise outdoor activities: If your dog goes outside, keep them on a leash and avoid areas where birds congregate, such as parks, ponds, and bird feeders.
- Clean up bird feeders: If you have bird feeders, clean them regularly and keep the area around them clean to reduce the risk of contamination.
Practice Safe Feeding Habits:
- Avoid raw meat: Do not feed your pets raw meat, especially poultry. Raw meat can be contaminated with H5N1 and other pathogens.
- Choose cooked or commercially prepared pet food: Opt for commercially prepared pet food that meets safety standards or cook meat thoroughly before feeding it to your pet.
- Avoid unpasteurized dairy: Do not give your pets unpasteurized milk or other dairy products, as they can also be a source of H5N1 infection.
Maintain Good Hygiene:
- Wash your hands: Wash your hands thoroughly with soap and water after handling birds, raw meat, or pet food.
- Clean pet items: Regularly clean and disinfect your pet’s food and water bowls, toys, and bedding.
- Clean your shoes: If you’ve been in areas where birds congregate, clean your shoes before entering your home to avoid tracking in the virus.
Suspect H5N1 in Your Pet? Early Action is Key
If your dog or cat shows signs of H5N1, contact your vet immediately. Quick action can help protect your pet and others. Early treatment can often improve a pet’s prognosis. Plus, isolating and treating an infected pet helps prevent the virus from spreading.
Stay informed about H5N1’s impact on pets with updates on this blog. If you have additional questions about H5N1, contact us or your family veterinarian.
Author:
James Woods DVM, MS, DACVIM (SAIM)
Ph: (912) 721-6410
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