UW Vet lab ID's flu strain impacting NYC shelter cats
Nik Hawkins, University of Wisconsin
Madison — The Wisconsin Veterinary Diagnostic Laboratory at the University of Wisconsin-Madison has identified the influenza A strain involved in an outbreak among cats in a New York City animal shelter as low pathogenic avian influenza H7N2, a rare subtype that has not been found previously in domestic felines.
The Shelter Medicine Program at the UW-Madison School of Veterinary Medicine is working closely with New York City's Manhattan Animal Care Center (ACC-Manhattan) and the New York City Health Department to manage the situation, which includes establishing a quarantine facility while the Manhattan center is disinfected.
Cats that have contracted the H7N2 strain in the shelter have displayed upper respiratory symptoms such as runny nose, congestion, persistent cough and lip smacking, but the illness has not been severe. One cat was euthanized after developing pneumonia. No other species of animals from the shelter, including dogs, have tested positive for the virus.
"While we are concerned about this new infection, the cats are experiencing only mild to moderate illness, but a few have developed pneumonia," says Sandra Newbury, clinical assistant professor at the veterinary school and director of the UW Shelter Medicine Program. "Many of the cats who were initially ill are already recovering. We do want people to be aware of what is happening, but influenza infection is unlikely in cats that have not had contact with cats from New York City's Manhattan Animal Care Center."
The first cases of influenza at the shelter were reported in late November when a private company, IDEXX Reference Laboratories, tested sick cats housed at ACC-Manhattan. The shelter then approached the UW Shelter Medicine Program and WVDL for more assistance since both helped manage outbreaks of a different strain of influenza that affected dogs and cats in the Midwest earlier this year and in 2015.
Further testing at WVDL found additional positive samples and led to identification of the H7N2 strain, a finding that has been verified by the U.S. Department of Agriculture's National Veterinary Services Laboratories. The California Animal Health and Food Safety Laboratory at the University of California, Davis also confirmed the presence of H7N2 influenza virus after IDEXX provided samples to that lab for testing.
First transmission among cats
"This is the first time H7N2 has been detected and transmitted among domestic cats," says Kathy Toohey-Kurth, clinical professor and head of the WVDL's virology section.
Several cases of H7N2 were found in commercial poultry in the United States between 2000 and 2006, and it may be able to spread to other animals. There have been only two cases of H7N2 found in humans, and both cases ended with full recovery. The virus is thought to pose low risk to people. No human infections related to this case have been identified to date.
While influenza infection is unlikely in cats that have not had contact with infected felines from the shelter, owners whose animals show signs of influenza should contact their veterinarian for instructions. Cats suspected to be infected with the virus should be housed separately from other animals and precautions should be taken to prevent spread of the virus on hands and clothing.
"We'll continue to work with the shelter to help manage the case and offer testing to any cats in rescue groups that are affected," says Newbury. "We are hoping that offering this kind of diagnostic support will help rescue groups identify if they have cats with the virus so they can isolate them in order to stop the spread."
Diagnostic testing conducted by the WVDL for animals that have come from the New York City shelter since Nov. 12 will be paid for by a generous gift from Maddie's Fund, a family foundation that seeks to "revolutionize the status and well-being of companion animals."
Shelters and rescue groups may contact the UW Shelter Medicine Program at uwsheltermedicine@vetmed.wisc.edu with testing inquiries or questions regarding influenza in cats and dogs, and can look for updates at www.uwsheltermedicine.com. More details about the program's partnership to provide diagnostic testing for shelters can be found on its diagnostic testing webpage.