The number of whitetail deer found with a fatal brain disease in southwest Wisconsin jumped to 130 animals Friday, with the discovery of another 36, the state Department of Natural Resources reported.

All were killed within the three-county area where the state wants to try to eradicate the chronic wasting disease from the herd, the agency said.

The 36 deer are the biggest number of animals to be found with disease in a single report by the DNR since the disease was discovered near Mount Horeb in February 2002. And for the first time, more deer with the disease have now been found in Iowa County than in Dane County.

The newest test results continue to show about 2 percent of the deer in the Mount Horeb area are inflicted with the incurable disease.

Until it was found in Wisconsin, the sickness had never been found east of the Mississippi River. It jeopardizes the state’s $1 billion hunting industry.

The disease creates sponge-like holes in a deer’s brain, causing the animal to grow thin, act abnormal and die. Although there is no scientific evidence the disease can infect humans, people are advised not to eat an infected deer.

The DNR is nearing the end of testing the brains of more than 40,000 deer heads that were submitted by hunters across the state last fall in an unprecedented attempt to find out how widespread mad-deer disease exists in the herd.

Friday’s weekly update showed 35,196 samples — or 88 percent — had been analyzed in a laboratory.

Of the diseased deer found so far, 68 were in Iowa County, 60 were in Dane County, one in Richland County and one in Sauk County.

Only six deer with the disease have been found outside the 411-square-mile eradication zone where the DNR wants all the deer killed to try to eradicate the disease from the herd. Those six were found in the so-called management zone nearby.