BILLINGS, Mont. — A cow has tested positive for brucellosis, a serious livestock disease that had been declared nonexistent in U.S. cattle earlier this year, according to a published report. Although it can cause pregnant cows to abort their calves, transmission to humans is rare and consuming animals with the disease is not considered dangerous, state officials said. Montana ranchers now must undergo an expensive testing program before shipping cattle out of state and will have to increase vaccinations. The state will also lose its federal brucellosis-free status until it can demonstrate it has the disease under control. The recent case was discovered late last month in the Paradise Valley, north of Yellowstone National Park, during testing of a small herd of cattle. Confirmation came earlier this week, following a second positive test conducted at a federal lab in Iowa.

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