MONROVIA - Foothills residents are being warned about a spreading outbreak of deadly distemper discovered in gray foxes that could infect unvaccinated pet dogs.

Signs of the disease first popped up in July in Monrovia. Since then, however, the outbreak has spread west into Sierra Madre and La Ca ada Flintridge, with suspected cases also discovered in Arcadia, Pasadena, Glendale and, most recently, Tujunga.