Virulent Newcastle disease, formerly known as exotic Newcastle disease, is a contagious and fatal viral disease affecting the respiratory, nervous and digestive systems of birds and poultry. The disease is so virulent that many birds and poultry die without showing any clinical signs.
As of April 17, 2020, USDA has confirmed 476 premises in California as infected with vND, including 262 in Riverside County, 164 in San Bernardino County, 46 in Los Angeles County, 1 in Ventura County, 1 in Alameda County, and 1 in San Diego County. USDA also confirmed 1 infected premises in Utah County, Utah and 1 infected premises in Coconino County, Arizona.
| Date Confirmed | State | County | Types of Birds |
| February 25, 2020 | California | San Bernardino | Backyard exhibition chickens |
| February 21, 2020 | California | San Bernardino | Backyard exhibition chickens |
| February 18, 2020 | California | San Bernardino | Backyard exhibition chickens |
| January 13, 2020 | California | San Bernardino | Backyard exhibition chickens |
| January 8, 2020 | California | San Bernardino | Backyard exhibition chickens |