Poultry owners in California are being urged to remain alert to the threat of avian influenza following recent detections of the highly pathogenic virus in Sutter and Sonoma counties. Animal disease emergency responders are currently working with flock owners in both locations to contain the spread.
Maurice Pitesky, a poultry specialist with University of California Cooperative Extension in the School of Veterinary Medicine at UC Davis, emphasized that “disease risk is dynamic, influenced by weather, wildlife movement and human activity.” He explained that changes in temperature can cause wild waterfowl carrying the virus to migrate within the state. While migratory birds may leave an area after introducing the virus, resident waterfowl can continue spreading it as the pathogen persists in water, air, and soil.
Many backyard chicken coops and poultry farms are located near bodies of water used by migratory birds. Even when these birds are not present, their viruses can linger in environmental sources. Pitesky noted that factors such as precipitation, ground moisture, temperature, and crop development influence waterfowl activity: “It’s just a dynamic situation.”
Bird flu outbreaks often follow increases in local waterfowl populations within 2.5 miles of affected farms by three to ten days. As a result, Pitesky recommends that poultry owners assess not only their immediate property but also surrounding conditions.
“When thinking about protecting our backyard flocks from infectious diseases carried by wildlife, we have a tendency to focus solely on the biosecurity of the coop and the immediate area around the coop,” he said. “However, because of diseases like highly pathogenic avian influenza, which are primarily carried by wildlife, we need to also think about understanding potential habitat in our neighborhoods.” He added: “For example, if you have a pond that is a couple of blocks from your house, migratory waterfowl such as ducks and geese are likely to roost on the pond and fly over while looking for feeding areas such as lawns and golf courses.”
To help prevent disease introduction into backyard flocks or small-scale farms, Pitesky outlined several biosecurity measures:
– Keep poultry separated from outside environments using barriers such as walls or wire mesh.
– Use fully enclosed coops with solid roofs; cover outdoor runs with netting or roofing.
– Install hardware cloth (¼–½ inch mesh) on all openings.
– Prevent access to open water sources like puddles or ponds; provide only municipal or well water.
– Elevate feeders and store feed securely; clean up spills promptly.
– Regularly clean footwear and equipment before entering poultry areas.
– Limit visitors’ access; avoid sharing equipment unless disinfected.
– Quarantine new birds for two to four weeks before introducing them.
– Isolate sick or dead birds immediately; consult veterinary services for guidance.
Pitesky also advises mapping nearby wildlife habitats—such as rivers or wetlands—to better understand exposure risks beyond one’s own property. He suggests evaluating whether flocks are near major bird migration routes or stopover sites. Recognizing species commonly visiting property perimeters is important since even healthy-seeming wild birds can carry pathogens.
He warns against behaviors that increase risk: “Visiting parks, wetlands or hunting areas before tending poultry” or “sharing tools or footwear between outdoor activities and poultry care.”
While eliminating all risk from wildlife is impossible—”the goal is risk reduction,” he said—communicating these risks clearly among household members helps ensure consistent prevention practices.
“In the big picture,” Pitesky concluded, “in a world of HPAI [highly pathogenic avian influenza], biosecurity and risk assessments are more complicated and dynamic than the coop.”
The impact extends beyond individual backyards: sick chickens can contribute to regional outbreaks affecting neighbors’ flocks as well as commercial operations.
UC Agriculture and Natural Resources (UC ANR), affiliated with the University of California, shares science-based practices statewide through research centers across diverse ecosystems (source). The organization operates offices throughout all 58 California counties (source) and supports communities via outreach initiatives designed to improve well-being (source).
For more information about keeping poultry safe from disease visit UC Cooperative Extension Poultry.