FLORENCE, Ariz. (AP) - A steer brought into Arizona to be used as rodeo stock has tested positive for bovine tuberculosis.

The state Agriculture Department says the steer was part of a rodeo stock operation based in Pinal County. The operation has been quarantined.

The steer tested negative when it was brought into the U.S. But it tested positive when it was retested so it could be sent to another state. It can take several months for exposure to show up in tests.

There is no cure for TB in cattle. Cattle exposed to the disease must either be tested or killed.

Arizona has been free of the disease since 1978.

Copyright 2011 The Associated Press.