CHICAGO (AP) — County and state health officials in Illinois are testing feral cats and warning residents to have their pets vaccinated after two outdoor cats tested positive for the disease in northern Illinois and western Missouri.

Cook County Animal and Rabies Control issued the warning Tuesday.

The cats found to have rabies in the past two weeks were in Ogle County, Illinois, and Cass County, Missouri.

Cook and nearby counties have increased surveillance for the disease, which is often fatal to animals and can be passed on to people from the bite of an infected animal.

Animal and Rabies Control Administrator Dr. Donna Alexander says finding rabies in cats is unusual.