Two more cases of debilitating deer disease have been confirmed in Mississippi, bringing the total to six.

The Mississippi Department of Wildlife, Fisheries and Parks tells the Clarion Ledger that tests confirm two deer shot by hunters in Marshall County had chronic wasting disease. The north Mississippi county earlier reported its first case.

The contagious and fatal neurological disease causes deer to have tremors and other movement problems and lose weight. Issaquena County has reported two cases, while Pontotoc County has reported one.

The disease is present in 25 other states. Tennessee has confirmed 24 cases in two counties bordering Mississippi.

Wildlife Bureau director Russ Walsh says Mississippi tested about 6,000 deer in the last year to determine the disease’s prevalence.

Officials encourage hunters to submit killed deer for testing.