Research Update: When Fur and Feather Meet

When Fur and Feather Meet

Posted by Gail Keirn, APHIS Legislative and Public Affairs

Striped skunks and cottontail rabbits are common visitors to farms across the country. They also frequent riparian areas and wetlands that are home to many waterfowl species. Normally, this wouldn’t be much cause for concern. Yet, a recent study by National Wildlife Research Center (NWRC) scientists (part of the USDA-APHIS Wildlife Services program) demonstrated that skunks and cottontails can become infected with and shed some avian influenza viruses in a controlled setting—making them potential carriers of the viruses to areas near commercial and backyard poultry farms.

“When wildlife and poultry interact and both can carry and spread a potentially damaging agricultural pathogen, it’s cause for concern,” notes NWRC research wildlife biologist Dr. Jeff Root.

Root is one of several NWRC researchers studying the role wild mammals may play in the spread of avian influenza viruses. In experiments with captive striped skunks, cottontail rabbits, and mallards, Root discovered that skunks and cottontails indirectly transmitted low pathogenic avian influenza (LPAI) A virus to mallards.

First, striped skunks and cottontail rabbits were inoculated with LPAI. Then, inoculated skunks and uninoculated mallards were housed in “mirrored” pens outfitted with the same items. After several days, the animals switched pens exposing the mallards to potentially LPAI contaminated items in the skunk pens. In a similar experiment, inoculated cottontails were co-housed with uninoculated mallards to determine if the mallards could become infected with LPAI through shared water and food sources. One of the four mallards exposed to the skunk pens and one of the five mallards exposed to the cottontails became infected.

 “Several findings from the experiments are important,” adds Root. “First, skunks and cottontails can acquire and shed LPAI virus. Second, skunk and cottontail behavior impacts where the virus is shed. And third, since mallards must ingest enough virus to become infected, virus transmission is strongly tied to where and when skunks and cottontails shed the virus and whether mallards frequent that space.”

 “We know from studies with captive animals it is possible for some mammals to spread some LPAI viruses, now we need to figure out how likely such spread is occurring in the wild,” concludes Root.

Experts note more field studies are needed to better understand the LPAI disease risks associated with small mammals at farms.  The best way to prevent avian influenza at your farm is by consistently using appropriate biosecurity measures.  The USDA and its industry partners provide a list of recommended biosecurity measures online.

For more information, please contact nwrc@aphis.usda.gov.