Avian Influenza in Companion Animals FAQ

November 6, 2006

Contents


 

AI and companion animals

Q: Is it true that cats can get avian influenza?

A: Although cats are not usually susceptible to influenza type A infections, results of a research study published in September 20041 demonstrated that domestic cats can become infected with the H5N1 highly pathogenic avian influenza (HPAI) virus and are capable of transmitting the virus to other cats. In February 2006, authorities in Germany reported that a domestic cat had died from H5N1 HPAI infection. That cat lived in the northern island of Ruegen, where more than 100 wild birds were believed to have died of the disease. The cat was probably infected by eating one of those infected birds. In March 2006, three cats in Austria were confirmed to be ill with the H5N1 HPAI virus; these cats did not die and were among 170 living in an animal shelter where the disease had been detected in chickens a month earlier. In August 2006, a confirmed case of H5N1 HPAI infection in a domestic cat in Iraq was reported in Emerging Infectious Diseases.2 Prior to these cases, there had been unconfirmed reports of H5N1 HPAI infection in domestic cats in Southeast Asia.

In Southeast Asia, avian influenza (AI) has also been diagnosed in captive large cats. In December 2003, two tigers and two leopards that were fed fresh chicken carcasses from a local slaughterhouse died at a zoo in Thailand. An investigation identified H5N1 HPAI in tissue samples from those cats. In February and March 2004, the virus was detected in a clouded leopard and white tiger, respectively, both of which died in a zoo near Bangkok. In October 2004, 147 of 441 captive tigers in a zoo in Thailand died or were euthanatized as a result of infection after being fed raw chicken carcasses infected with the H5N1 HPAI virus. Investigation of the deaths suggested that at least some tiger-to-tiger transmission occurred in that facility.

Clinical signs in naturally infected cats have not been described, but signs in experimentally infected cats include fever, listlessness, difficulty breathing, conjunctivitis (swelling and redness of the membranes around the eyes) and death. Pet owners should remember that these signs are commonly encountered in cats with other diseases. Therefore, confirmation of infection with H5N1 HPAI virus requires submission of appropriate diagnostic samples to a laboratory.

1Kuiken T, Rimmelzwaan G, van Riel D, et al. Avian H5N1 influenza in cats. Science 2004;306:241.

2Yingst SL, Saad MD, Felt SA. Qinghai-like H5N1 from domestic cats, northern Iraq [letter]. Emerg Infect Dis [serial on the Internet]. 2006 Aug. Available at: http://www.cdc.gov/ncidod/EID/vol12no8/06-0264.htm

Q: What is the incubation period of highly pathogenic H5N1 avian influenza virus in cats?

A: In experimentally infected cats, signs were seen as early as 2 days after inoculation. In a single report describing a naturally infected cat, signs were observed 5 days after the cat ate the carcass of an infected pigeon.

Q: How do cats become infected? Can they spread the virus?

A: All natural H5N1 highly pathogenic avian influenza (HPAI) infections in domestic cats reported to date appear to have been associated with outbreaks in domestic or wild birds and acquired through ingestion of raw meat likely infected with the H5N1 HPAI virus.

Fortunately, there is no evidence to date that domestic cats play a role in the natural transmission cycle of H5N1 HPAI viruses. There have been no known cases of human avian influenza (AI) resulting from exposure to sick cats, and there have been no outbreaks of AI among domestic cat populations. Cats in a laboratory/research setting have been shown to be able to spread the H5N1 HPAI virus to other cats, but it is not known whether such spread occurs under natural conditions.

Q: How is the virus shed by companion animals?

A: In experimentally infected cats, the virus was detected by swabbing nasal, pharyngeal (throat), and rectal tissues. "Shedding," as it applies to viruses, means that the animal's secretions and/or feces contain viral particles that may infect other animals or people. Although it has not been confirmed, it is reasonable to assume that virus may be shed in oral and respiratory secretions and feces from naturally infected cats. Evidence suggests that the H5N1 highly pathogenic avian influenza (HPAI) virus is not shed in the same quantities from cats as it is from birds, and that the risk posed to humans by infected cats is low. Based on what is known from experimental infection and a single case of clinically apparent avian influenza in a dog, the risk of transmission from this species should also be very low.

Practicing good hygiene (e.g., washing hands and frequently disinfecting surfaces) and limiting contact with pets showing signs or respiratory illness (e.g., coughing, sneezing, wheezing, nasal discharge) are reasonable precautions if a companion animal is suspected to be infected with H5N1 HPAI.

Q: What is the current risk that a cat will become infected with highly pathogenic H5N1 avian influenza in the United States?

A: The strain of H5N1 highly pathogenic avian influenza (HPAI) that has circulated in Asia, Africa, and Europe has not yet been identified in the United States, so the risk of a cat contracting the disease in this country is currently very low.

Although the risk of feline infection is also low in Europe, increases in the number of wild birds affected and the death of the cat in Germany have caused the European Centre for Disease Prevention and Control to issue preliminary recommendations for cat owners living in H5N1 HPAI-affected areas. These precautionary measures include keeping domestic cats indoors to prevent exposure to potentially infected birds, avoiding contact with free-roaming and feral cats living outside the home, and avoiding feeding raw poultry to cats. Owners of ill cats, particularly those known or suspected to have been exposed to sick or dead birds, are encouraged to have their cats examined by a veterinarian.

Q: My cat ate a dead bird (or was found with a dead bird in its mouth). What do I do?

A: Because H5N1 highly pathogenic avian influenza (HPAI) virus has not yet been detected in the United States, it is unlikely that the bird would pose a risk of H5N1 HPAI infection to your cat, and no special precautions unique to avian influenza (AI) prevention and control are warranted.

If the virus is found in the United States, and if it is found to infect wild birds upon which cats are likely to prey, you should contact your veterinarian for assistance. Depending on the guidance developed by state and federal authorities, he or she may recommend that you confine the cat indoors in a separate room or cage away from humans and other animals for 7 to 10 days and avoid being scratched or bitten. If the cat remains healthy throughout this time, your cat probably poses a minimal risk of infection to other animals and people.

If your cat develops signs of disease consistent with AI infection, your veterinarian should be notified immediately and the cat should continue to be confined to minimize its contact with people and other animals. Wear disposable gloves and disinfect all surfaces the cat may have contacted, including food and water dishes and litter boxes. Wash your hands thoroughly after disinfecting surfaces and equipment and after handling potentially exposed cats.

Q: What are some recommended measures for preventing highly pathogenic H5N1 avian influenza virus infection in free-roaming and feral cats?

A: If H5N1 highly pathogenic avian influenza (HPAI) virus appears in the United States, and if it is found to infect species of small animals that cats would likely eat or prey upon (e.g., mice, small species of birds), then free-roaming and feral cats might be at risk of infection. However, in areas of Europe where large numbers of wild birds were found to be infected, only a very small number of cats potentially exposed to the virus became infected themselves.

Although the risk to caretakers of feral cat colonies would likely be quite low, the following precautions should be taken if H5N1 HPAI virus were to appear in the United States:

  • Minimize direct contact with feral cats.
  • Avoid being scratched or bitten.
  • Wear disposable gloves when handling food and water dishes, cages, and other surfaces that cats may have contacted, and wash hands afterwards.
  • Regularly clean and disinfect food and water dishes and cages.
  • Consult with your veterinarian if you have any additional questions or concerns.

Q: Can dogs become infected with avian influenza?

A: Like cats, dogs are not usually susceptible to avian influenza (AI) viruses; however, an unpublished study carried out in 2005 by the National Institute of Animal Health in Bangkok indicated that dogs could be infected with the virus. No clinical disease was detected in association with that infection. This limited information is insufficient to determine how susceptible dogs are to the virus.

In October 2006, a case of fatal infection of a dog with the N5N1 AI virus was described in Emerging Infectious Diseases.1 The dog became infected after eating the carcass of an infected duck during the second wave of H5N1 highly pathogenic avian influenza (HPAI) outbreaks in Thailand in October 2004. Approximately 5 days after eating the duck, the dog was febrile, panting, and lethargic; it died six days after eating the duck. Necropsy revealed severe congestion and fluid accumulation in the lungs, and congestion of the spleen, kidneys, and liver. View the report on the CDC Web site.

1Songserm T, Amonsin A, Jam-on R, et al. Fatal influenza A H5N1 in a dog. Emerg Infect Dis [serial on the Internet]. 2006 Nov. Available from http://www.cdc.gov/ncidod/EID/vol12no11/06-0542.htm.

Q: Is "canine influenza" the same thing as H5N1 avian influenza in dogs?

A: No. The canine influenza virus is a type A influenza virus of subtype H3N8 and is more closely related to the equine influenza virus. View more information about canine influenza on the AVMA Web site.

Q: What are the clinical signs of highly pathogenic H5N1 avian influenza in dogs?

A: Based on the very limited information available and extrapolating from other species, it is possible that H5N1 highly pathogenic avian influenza in dogs could appear as respiratory, intestinal, reproductive, or neurologic disease.

Q: How do dogs become infected? Can they spread the virus?

A: There is not enough information available about H5N1 highly pathogenic avian influenza (HPAI) infection in dogs to know how infection would develop. Domestic cats in Europe appear to have become infected by eating infected poultry or wild birds. Details concerning a case of H5N1 infection in a dog in October 2004 were recently published; the dog was infected after it ate the carcass of an infected duck. View the report on the CDC Web site.

Q: What is the current risk that a dog will become infected with highly pathogenic H5N1 avian influenza virus in the United States?

A: At the moment, there is little risk of a dog in the United States becoming infected with H5N1 highly pathogenic avian influenza because the virus that has circulated in Asia, Europe, and Africa has not yet been found in the United States.

Q: Can my dog or cat get highly pathogenic H5N1 avian influenza virus infection from eating poultry products?

A: Poultry products are only a risk if they come from infected birds and are eaten while raw (unprocessed). It may be possible for cats and dogs to contract H5N1 highly pathogenic avian influenza (HPAI) by eating infected raw poultry products. However, because H5N1 HPAI has not yet been found in poultry in North America and because poultry contained in commercial pet foods is generally cooked and processed, it is considered safe to feed pets commercially processed foods containing poultry products.

Q: Can my cat/dog get highly pathogenic H5N1 avian influenza virus infection from eating a raw meat diet?

A: If your cat, and potentially your dog, consumed raw meat from an infected bird, it may be possible for them to become infected with H5N1 highly pathogenic avian influenza (HPAI). However, H5N1 HPAI virus has not been detected in wild birds or other animals in the United States at this time. If or when it does appear, safeguards established by governmental agencies should help prevent outbreaks in commercial bird flocks. This makes it very unlikely that infected poultry meat would ever reach the marketplace. The risk, therefore, of a pet becoming infected by eating uncooked poultry is extremely low. Nevertheless, for a variety of reasons, feeding raw meat to pets is not recommended. The risk of Salmonella, Campylobacter, and E. coli infections is increased by feeding raw meat to dogs and cats, and is far greater than the risk of H5N1 HPAI virus infection.

Q: Can companion birds be infected with H5N1 highly pathogenic avian influenza virus? What are the clinical signs in companion birds?

A: Yes, all birds are susceptible to infection with avian influenza (AI) viruses. However, because H5N1 highly pathogenic avian influenza virus has not yet been identified in the United States, risk of infection for companion birds is very low.

If affected, companion birds may show signs of respiratory (e.g., discharge from the nose and/or eyes, sneezing, ruffled feathers, or labored breathing), gastrointestinal (e.g., diarrhea), and/or neurologic (e.g., incoordination, depression) disease and be lethargic. There are no clinical signs that are unique to AI infection in companion birds, and some infected birds may show no signs of illness.

Q: What is the risk that my bird will become infected with H5N1 highly pathogenic avian influenza virus? Can it spread the virus if it becomes infected?

A: Even if H5N1 highly pathogenic avian influenza (HPAI) were to be detected in the United States, indoor birds would be at very low risk of becoming infected. Should H5N1 be detected, birds housed outdoors should be protected from contact with wild migratory birds (especially waterfowl and shorebirds), their droppings, and water frequented by waterfowl and shorebirds. If companion birds become infected, it may be possible for them to spread the virus.

Q: Is there a vaccine available to protect companion animals against highly pathogenic H5N1 avian influenza virus?

A: Currently, there is no USDA-licensed vaccine against H5N1 highly pathogenic avian influenza infection available for use in companion animals in the United States.

Q: There are wild birds outside—can I let my dog/cat out?

A: The H5N1 HPAI virus is not present in the United States at this time. Therefore, wild birds, including Canada Geese, turkeys, and song birds, pose little risk to you or your pets. Keeping cats and dogs indoors, unless being walked on a leash or otherwise confined, is best for their safety, regardless of risk of infection with the virus. Cats and dogs allowed to roam outdoors are exposed to many dangers, including automobile injuries, animal bites, poisoning, and other infectious diseases.

Q: Can my pet catch "bird flu" if it's not a bird?

A: In addition to wild and domestic birds and poultry, humans, domestic cats, and dogs, we know that pigs, palm civets, cynomolgus macaques, New Zealand white rabbits, stone martens, tigers, leopards, ferrets and rats can become infected with the H5N1 highly pathogenic avian influenza (HPAI) virus. It's possible that other mammals may also be susceptible to H5N1 HPAI infection.

Q: Can I give highly pathogenic H5N1 avian influenza virus to my animal?

A: Transmission of influenza viruses depends on exposure to the virus and adaptation by the virus to the new host. Transmission of H5N1 highly pathogenic avian influenza (HPAI) virus from humans to animals (including cats, dogs, and birds) has not been documented, but may be theoretically possible under certain circumstances. Because H5N1 HPAI can cause illness and death in humans, the health of the pet owner and their potential to transmit the virus to other humans is the primary concern for public health officials, including veterinarians.

Q: Can my pot-bellied pig spread highly pathogenic H5N1 avian influenza virus?

A: Certain mammalian species are known to be susceptible to infection with the H5N1 highly pathogenic avian influenza (HPAI) virus, including pigs. Because the rate of infection for this virus in pigs is very low, and because the H5N1 HPAI virus has not yet been found in North America, pot-bellied pigs are not considered to be reservoirs for the virus and should not spread H5N1 HPAI. However, because there is much we do not know about H5N1 HPAI, infection control precautions similar to those recommended for other companion animal species should be followed if H5N1 HPAI is identified in the United States.

Q: Where do I look for additional information and resources?

A: Links to Information about Avian Influenza

American Veterinary Medical Association Influenza Resources
American Association of Avian Pathologists Avian Influenza Position Statement
Association of Avian Veterinarians (AAV)
National Association of State Public Health Veterinarians (NASPHV)
Department of Health and Human Services Information on Pandemic Flu and Avian Influenza
Centers for Disease Control and Prevention (CDC) Avian Influenza (Bird Flu)
Human Infection with Avian Influenza A (H5N1) Virus: Advice for Travelers
USDA Avian Influenza (Bird Flu)
USDA Biosecurity for the Birds
USDA-APHIS Veterinary Services Area Offices (listing by state)
Designated State Veterinarians (listing by state)
Designated State Public Health Veterinarians (listing by state)
USDA-APHIS Wildlife Services (listing by state)
FDA and Pandemic/Avian Influenza
Guidance for Protecting Workers Against Avian Flu
EPA: Registered Antimicrobial Products with Label Claims for Avian (Bird) Flu
US Poultry & Egg Association
World Health Organization (WHO) Avian Influenza Resource
Food and Agriculture Organization (FAO) of the United Nations (Avian Influenza)