HELENA — State livestock officials said Thursday that more tests for a disease dreaded by the ranching industry have turned up negative, although many more tests remain and it could be months before Montana knows if it keeps its brucellosis-free rating.

Montana Department of Livestock officials were buoyed Thursday by tests results on 1,752 head of cattle that showed no more cases. If another case of the disease, first found last month in one herd, turns up in Montana, then the state loses its disease-free status.

“You don’t want to say breathe easy, because you can’t until we are done,” said Department of Livestock executive officer Christian Mackay. “But we are certainly encouraged with the results that are coming in.”

Tests are still planned on at least 600 more head of cattle. And the investigation has moved out of state to a Wyoming herd that may have come in contact with the Bridger herd hit with the disease last month.

Officials have been testing cattle that could have crossed paths with the original herd, such as by sharing a fence line. That original herd of 352 cows turned up seven confirmed cases of brucellosis.

Montana ranchers had successfully kept the disease, which is still found in Yellowstone National Park wildlife, out of Montana livestock since 1985.

Wyoming will start tests next week on about 330 yearling heifers and 180 cows at a ranch near Cowley, Wyo. They said it is unlikely the animals, which shared a fence line with the Wyoming herd, caught the disease.

Another herd that potentially came in contact with infected animals is currently on a summer grazing range larger than 100,000 acres and won’t be tested until the fall, the Department of Livestock said.

Officials said they are still tracking animals that could have had contact with the disease. Once found, if still alive, the animals will be tested.

“You never know till it’s all done,” Mackay said.

The state is getting close to testing animals that had direct contact with the Bridger herd. Tests will continue on herds that potentially shared animals, such as through livestock transactions.

Mackay said the state will remain on probation for two years. The state loses its disease-free status for any positive tests during that time.

The ranching industry says it could cost millions to eradicate the disease from the state if it again gains a foothold. Ranchers will also lose business opportunities.

The brucellosis outbreak prompted renewed calls from the livestock industry to crack down on bison that wander out of Yellowstone National Park close to cattle grazing areas.

Gov. Brian Schweitzer worked out an agreement with federal officials to truck one renegade group of bison back into the park if it comes out again — sparing a large group of calves from slaughter.