The niche world of pet rats has been warned about a virus that infected a handful of breeders.
In wake of a national warning that eight people who breed rats have become ill through contact with their infected pet rats, Garden State "ratteries" are on the lookout for the virus.
The Seoul virus - related to the more common Hantavirus that hits rodents - has sickened workers in the rat-breeding industry in two states, Wisconsin and Illinois, according to the U.S. Centers for Disease Control and Prevention. It is the first known outbreak of the virus in the United States.
The virus is not spread from person to person, and cannot be transmitted to other types of pets, the CDC said.
"It's obviously on my radar, but because it's a really rare virus I'm not worried about it. I know my rats are not affected," said Katie Swisshelm, who operates Farmhouse Rattery out of her home in Sussex County. "Because of this, everyone who deals with rats is going to be on the watch."
Most of her rats are bred from original stock she acquired years ago; any newcomer is quarantined until its health is proven. She doesn't let strangers have any contact with them, and when she adopts them out, she meets those customers off-site.
Those precautions are for both the rats and her family. "I have kids here, so obviously I need to be super careful," she said. She has three children, 10, 4 and 3, and says they have never been bitten during the more than 8 years she has kept rats.
Rats are an under-the-radar "pocket pet" with their own small community of enthusiasts.
"They make great pets. They're personable and sweet, with tons of personality, like a dog," said Swisshelm, who grew up raising goats in 4-H. Rats are good if for pet-lovers don't have a lot of room, she said, or have a schedule that can't accommodate a dog's need to be walked.
"Their biggest downfall is that they have such a short lifespan," she said. "You get attached, but they only last two or three years."
Most home-based rat breeders raise rats to be sold or "adopted out" as pets for a modest sum. Rats that are grown to be food for other animals are typically sold frozen, Swisshelm said. She said she breeds for temperament and hardiness, while others prefer to breed for color or novelty. And yes, those owners display them at rat shows in much the same way people show off their pets at dog shows.
The CDC announced last Friday that it had documented the first known outbreak of Seoul virus associated with pet rats in the United States. The virus is carried by wild Norway rats worldwide. People get the virus through contact with a rat's infectious body fluids, or through a bite.
A home-based rodent breeder in Wisconsin was hospitalized last month with fever, headache and other symptoms. Analysis of a blood sample confirmed the Seoul virus, and further testing of a close family member who also handled the rats turned up a second case. Both people recovered.
However, a follow-up investigation of several rat breeders that had supplied the initial patient's rats revealed another six cases of the virus among workers at two Illinois "rat breeding facilities." The CDC did not indicate if those facilities were small, home-based ratteries, or larger breeding operations.
The Seoul virus usually produces a milder illness than the classic Hantavirus. Some people don't even display any symptoms, while in rare cases it can become severe enough to produce kidney failure.
The CDC advised anyone who has been bitten by a pet rat to see a doctor.
Kathleen O'Brien may be reached at kobrien@njadvancemedia.com. Follow her on Twitter @OBrienLedger. Find NJ.com on Facebook.