The “Swine flu” has been referred to by many other names: North American Influenza A virus, H1N1 virus, and Mexican flu. The Center for Disease Control (CDC) officially named the virus the 2009 H1N1 flu. The 2009 H1N1 flu virus was first reported in late March/early April of 2009 in central Mexico and the U. S. border states of California and Texas. Since then, the H1N1 virus has become a worldwide pandemic. The CDC has determined the 2009 H1N1 flu virus contains 4 viral sources (which is unusual for a flu virus): North American swine influenza virus, North American avian influenza virus, human influenza virus, and Asian plus European swine influenza viruses. [6]

Within the United States, the H1N1 virus has now been identified in pigs, people, domesticated cats and ferrets, plus, exotic cats (cheetahs). The U.S. Department of Agriculture (USDA) has confirmed 5 cases in cats (2 in Colorado and 1 each in Oregon, Iowa, and Pennsylvania) and 5 cases in ferrets (4 in Oregon and 1 in Nebraska). [2] Currently, there are no reported cases of H1N1 in dogs in the United States (however, canines are vulnerable to the Canine Influenza viral strain known as H3N8). Pet birds have been susceptible to other strains of flu, but, no cases of H1N1 have been reported. Only U.S. poultry (turkeys) have become infected with the H1N1 virus. [6]

Because H1N1 is a new influenza strain and there have only been a few cases of H1N1 flu in pets, veterinarians possess limited information about the symptoms and how the H1N1 flu impacts our pets. Pets with H1N1 may behave as if they aren’t feeling well, act lethargic, have a fever, and/or may appear to have a respiratory illness (e.g., sneezing, coughing, ocular/nasal discharge). Therefore, if your pet seems ill and/or appears to have the flu, your pet should be taken to a veterinarian for an exam as soon as possible and the veterinarian should be alerted if the pet has been exposed to someone with influenza.

The first feline infected with H1N1 was presented in October 2009 to a local veterinarian with a 3 – 4 day history of lethargy, lack of appetite, and harsh lung sounds. Since the cat had been kept indoors and was the only cat in the household, it seemed unlikely an infectious disease was the cause for the illness. After cardiac disease was ruled out, cytology and thoracic x-rays revealed a chronic lower respiratory inflammatory process (e.g., bacterial pneumonia). Interestingly, cultures of the lung contents were negative for bacteria. [5] Because the clients indicated they had been experiencing flu-like symptoms, the cat was tested for H1N1. The cat’s H1N1 positive diagnosis was confirmed in December 2009 by the Colorado State University’s Veterinary Diagnostic Laboratory using oral and nasal swab samples and by Iowa State University via blood serum sample. [2]

Treatment for the cat consisted of antibiotics as a precaution against secondary bacterial infections. Antibiotics, though, cannot directly treat any viral infection. As a result, some pets may have symptoms that will not respond to the antibiotic medical treatment. In addition to administering antibiotics, the treatment plan consisted of subcutaneous fluids and supportive therapy (e.g., plenty of rest and enticing the cat to eat). The cat’s condition substantially improved upon re-examination, but subsequent x-rays revealed a persistent, slow-resolving viral infection. [5] A licensed or approved H1N1 vaccine for our pets does not exist. In addition, the human H1N1 vaccine should not be administered to our pets. [6]

There are no published reports that an infected pet can transmit (or has transmitted) the H1N1 virus to a human (nor can humans become infected with the H1N1 by eating pork or turkey products). [6] Furthermore, follow-up tests performed at Iowa State University on the first 2 infected cats did not detect the H1N1 virus after they had recovered from the infection. Although, antibodies for the virus were identified, implying the cats’ developed immunity to the virus once they recovered. [5] So far, all of the affected domesticated cats and ferrets became infected after their owners reported that a family member(s) had been suffering from flu-like symptoms prior to their pets’ illnesses. Thus, the evidence suggests our companion animals are contracting and becoming ill with the H1N1 strain by their human caretakers. To date, the infected companion animals have experienced a mild respiratory illness and most of them have fully recovered. Only two pets have died from the H1N1 infection they contracted from their owners: one cat in Oregon and one ferret in Nebraska. [5]

As a preventative, people with the H1N1 flu (or any flu) should be careful and follow proper hygiene and sanitation practices when in contact with their pets. For example, we recommend that clients practice “social distancing” with their pets just as they would with people. People who are ill should wash their hands before handling their pets and, if possible, have someone else who is well feed and care for their pets. Just like people, pets are exposed to the H1N1 virus through aerosols (i.e., fluids released whenever someone sneezes, coughs, or touches their face and then a surface (e.g., H1N1 infected human kissing their pet)). [4] In addition, these recent incidents of H1N1 infections in our companion animals underscore the importance of keeping our pets healthy in order to reduce their risk of becoming ill. And if your pet becomes ill (especially if someone in the household experiences flu-like symptoms), owners should consult a veterinarian immediately.

All pets suspected of being or confirmed to be infected with H1N1 should be managed in the same manner as a pet with a viral respiratory infection (i.e., by employing standard veterinary medical quarantine, hygiene, and sanitation protocols). The Veterinary Diagnostic Laboratory at Colorado State University is testing pets for H1N1 as part of the U.S. Department of Agriculture’s National Animal Health Laboratory Network. [2] The standard test used to confirm the presence of the H1N1 virus is the polymerase chain reaction (PCR) test. However, animals must be actively shedding the virus for the PCR test to detect the H1N1 virus. [6] Thus, it is imperative that a nasal or oral swab sample be collected in the early phase of the pet’s illness. Hemagglutination inhibition on serum can also be used to confirm the presence of the H1N1 virus. [6] Locally, Schering-Plough, the manufacturer of the Canine Influenza Vaccine, is performing tests for the Canine Influenza (H3N8) on nasal or oral swabs for Family Pet Hospital canine patients possessing any suspicious respiratory illness.

The American Veterinary Medical Association (AVMA) is monitoring all reports of H1N1 cases in animals, posting updated reports, and maintaining a list of helpful resources at its web site under the Public Health section and Influenza link (http://www.avma.org/public_health/influenza/new_virus/default.asp).

References:

1. American Veterinary Medical Association (AVMA) H1N1 image provided via http://www.catvets.com/uploads/Images/logos/avma_h1n1.jpg

2. American Association of Feline Practitioners (AAFP) Newsroom 12/4/2009 article “Two Cases of H1N1 Confirmed in Colorado Cats” at http://www.catvets.com/newsroom/

3. Colorado State University Department of Public Relations 12/4/2009 article “Two Cases of H1N1 Confirmed in Colorado Cats” by Dell Rae Moellenberg at http://www.news.colostate.edu/Release/Print/4934

4. American Association of Feline Practitioners (AAFP) Newsroom 11/15/2009 article “Pigs, People, and now Pets” at http://www.catvets.com/newsroom/

5. Journal of the American Veterinary Medical Association (JAVMA) News 12/9/2009 article “Cats and Ferrets are latest to succumb to H1N1” by R. Scott Nolen with Greg Cima at http://www.avma.org/onlnews/javma/dec09/091215k.asp

6. American Veterinary Medical Association (AVMA) 2009 H1N1 Flu Virus Outbreak 12/4/2009 Updates at http://www.avma.org/public_health/influenza/new_virus/default.asp