The outbreak of monkeypox in the Midwest is focusing attention on a thriving cottage industry in Texas, where a handful of operators catch thousands of the rodents and ship them to pet stores around the nation.

Prairie dogs, once rising stars in the exotic pet industry, are now the top suspects in the Western Hemisphere's first incidence of monkeypox. Health officials have confirmed a total of five human cases of the disease — four in Wisconsin (search) and one in Illinois (search).

Forty-eight possible cases have been reported; no one has died of the disease.

The scare prompted investigators to scour seven states Tuesday for dozens of prairie dogs and other exotic pets sold by an Illinois distributor.

Prairie dog vendors in Texas (search) say they're not at fault.

"We supply a lot of prairie dogs ... and our animals are healthy," said Jasen Shaw, owner of U.S. Global Exotics. "We haven't got any animals dying here."

Investigators say 200 prairie dogs shipped from Shaw's company probably contracted monkeypox from a giant Gambian rat at a Chicago-area pet distributor. They are trying to trace anyone who bought a prairie dog at the store since mid-April.

They are also tracking a shipment of about 50 Gambian rats that a Texas importer received from Africa. Officials declined to identify the importer, who shipped some of the rats to the Chicago-area distributor.

Doug McBride, a spokesman for the Texas Department of Health, said no signs of monkeypox have been found in humans or animals so far in Texas.

A handful of businesses in Texas collect more than 20,000 prairie dogs each year on private land and sell them to people as far away as Japan, according to state officials.

Some go to companies like U.S. Global Exotics, located in a nondescript industrial building in Arlington, about 20 miles west of Dallas. Shaw's company sells thousands of animals — hedgehogs, chinchillas, reptiles, along with more mundane hamsters, guinea pigs and rabbits — to pet stores across the nation and overseas. He said he does not sell Gambian rats.

Orders for prairie dogs continue coming in, but Shaw cannot send the animals to stores because the U.S. Department of Agriculture (news - web sites) has temporarily banned the shipment of mammals.

The ban was put in effect so officials could search for the origin of monkeypox, a contagious and sometimes fatal disease normally found in West Africa.

Demand for prairie dogs is driven by people like Susan Bechtholt, who lives on a ranch in western Washington. Before the monkeypox outbreak, she paid $200 each for two black-tailed prairie dogs from Texas.

Bechtholt said the animals are cuddly, loving and smart.

"Each one has their own distinctive personality, and each one has their own little mannerisms," Bechtholt said.

In Texas, prairie dogs are varmints, unprotected by state laws and killed by the thousands by ranchers, farmers and state and federal animal control agencies. About four years ago, the state started requiring permits for commercial collectors.

Prairie dogs are found throughout the Great Plains. Their numbers have been reduced more than 95 percent as farming and housing has taken over their range, but there are still 200,000 to 300,000 acres of occupied prairie dog towns in Texas, officials said.

Monkeypox, which produces fever, rash, chills and aches, is a milder relative of smallpox. It has a mortality rate of 1 percent to 10 percent in Africa, but no humans have died in the United States, and U.S. officials believe better nutrition and medical treatment probably will prevent deaths.