The first case of bubonic plague in Montezuma County this year has been reported.
A house cat was diagnosed March 30 with the plague.
An epidemiologist thinks the cat caught from ingesting an infected rodent.
John Pape, of the Colorado Department of Public Health and Environment, says rodents are coming outside sooner than normal because of the warm weather.
That's causing the plague to spread earlier this year.
Pape says Mesa County had three cats with the plague last month and several squirrels diagnosed in February, Pape said.
The sickness is transmitted from infected fleas to prairie dogs, rabbits, ground squirrels and other rodents.
Montezuma has had one case of plague each of the last two years.