Livestock Health Post-Fire

Wildfires can expose livestock to injury through direct burns or inhalation of unhealthy air containing smoke and particulates. These particulates can build up in the respiratory system, causing a number of health problems including burning eyes, runny noses and illnesses such as bronchitis. Smoke can also aggravate heart and lung diseases such as congestive heart failure, chronic obstructive pulmonary disease, emphysema and asthma. Livestock that are burned by wildfires may experience shock, pain, and systemic complications.

Because little information is available to livestock producers or even veterinarians on the effects of fire and smoke on livestock, the following suggestions are offered to serve as a general guide.

• Provide plenty of fresh water. The consumption water keeps the airways moist and facilitates clearance of inhaled particulate matter. This allows the windpipe (trachea), large airways (bronchi), and small airways (bronchioles) to remove inhaled particulate material in smoke.
• If possible, limit exercise during and after (4-6 weeks) unhealthy air quality. Don’t force livestock to perform unnecessary activities or increase exercise that increase the airflow in and out of the lungs. Smoke contains particulates that can alter the immune system. Attempting to handle, move, or transport livestock during this time may aggravate the lungs, delay the healing process, and compromise the performance of livestock for many weeks or months.
• Recent research results indicate that forages affected by wildfire ash deposition are likely safe for livestock to consume. Wildfire ash was not found to increase the deposition of heavy metals in forages in areas relatively close to burned structures containing contaminants from household products, vehicles, businesses and residential chemicals.

Poultry Health and Egg Safety Post-Fire

Introduced pollutants after urban wildfires can impact the safety of eggs produced by backyard chickens. The chicken’s exposure to these contaminants may compromise eggs and post health risks to humans if consumed. By learning about potential hazards and taking appropriate precautionary steps to evaluate and reduce your flock’s exposure, backyard chicken owners can better protect themselves and increase the likelihood of producing safe, nutritious eggs in a post-fire environment.

After a wildfire, harmful contaminants are left behind in the soil and water. Chickens are especially prone to ingesting these contaminants through directly inhaling or ingesting toxic particles, ingesting contaminated soil with their feed, or drinking contaminated water sources. These contaminants can be ingested by backyard chickens and later be found in the edible portions of their eggs. Out of an abundance of caution, do not eat the eggs from chickens that have foraged in burnt areas.

To evaluate the risks of contaminants after a wildfire, it is important to know the quality of soil and water in your chickens’ foraging area. Testing the soil and water where your chickens forage and their eggs will inform you of the toxicity levels present and the safety of the eggs the chickens produce. It is recommended that you test your eggs to assess contaminant levels at least once post-wildfire.

How to Mitigate Risks and Protect Your Flock

To reduce the likelihood of your flock ingesting toxins and debris post-wildfire:

• Keep chickens from foraging near household hazardous waste, building materials, pesticides, fire suppression chemicals and other toxic materials. Presumably, until the source of contamination is removed, your chickens will continue to be exposed and your eggs will show levels of contamination.
• Place chickens on raised beds or a specific area in your yard with clean soil, mulch or other materials that can help reduce contact with toxic materials.
• Place chicken feed in a confined feeder that keeps the feed off the ground
• Avoid feeding unwashed garden scraps to your chickens from areas heavily affected by ash.
• Do not compost using shells of chicken eggs that were exposed or potentially exposed to toxins.
• Make calcium available to your chickens (e.g., free choice oyster shells) to prevent the absorption of lead,2 however most chickens will not consume calcium supplements unless they have a deficiency.

Can You Graze After a Wildfire?

Determining when to graze livestock after a fire can be a controversial and difficult decision. Much of the post-fire consideration depends on local site characteristics (percent slope, soil type), plant species composition, and intensity of the fire. After a fire has removed all vegetation, forage production will be about 50 to 70 percent of the amount on an undisturbed site in the following season; and down about 20 percent the second year. Only in the third year will the forge return to previous production.  After a high-intensity fire that leaves white ash, less than 25 percent as much forage will be produced on the burned site than on an unburned site for each of the next 3 years. 

Knowing that forage production will be reduced after a fire, the following grazing management practices applied can help buffer the consequences of an unintentional fire:

• Monitor burned areas to prevent overuse of vulnerable plants when they are trying to recover from wildfire. Newly germinated plants, or existing ones putting out new foliage, need to collect and store enough energy to develop healthy root systems.
• If economically possible, delay or limit grazing in burned areas as needed. Limiting grazing to light or moderate levels after fire will ensure there is adequate plant material (stubble) for continued growth in following years. If a pasture has been burned, letting it rest from germination through seed-set help improve plant vigor and restore the seedbed and litter.
• In unburned areas, maintain stubble to keep soils from washing away during the winter and early spring rains. This is particularly important in areas near streams and rivers to prevent soil and manure from washing into riparian areas. Retaining residual cover will also provide a nursery to the following year’s grass crop and provide additional forage than areas where all vegetation was removed.

References and Resources

Videos

Livestock, Rangelands, & Wildlife

	A Survey of Wildfire Ash Impacts on California’s Forage Crops Betsy Karle discusses how Cooperative Extension Advisors and Specialists have sampled a variety of forages throughout California to evaluate the impact of wildfire ash on feed quality and safety. Though the focus is on California forages, the guidance shared can benefit those in any area.
	Disaster Preparation for Commercial Livestock Operations Dan Macon, UC Cooperative Extension Livestock and Natural Resources Advisor, discusses disaster preparation for commercial-scale ranches in the Sierra Foothills and elsewhere. Ranching businesses face a specific set of challenges when it comes to protecting facilities and livestock – this short video includes information on the types of potential disasters (including wildfire) and on the importance of developing – and sharing – a written plan.
	Principles of Targeted Grazing, Managing livestock and Grazing for Fuel Load Reduction Dan Macon, UC Cooperative Extension Livestock and Natural Resources Advisor, discusses the principles of targeted grazing, including techniques for targeting specific types of vegetation, as well as animal husbandry, nutrition, and logistical considerations. This information can be used broadly in any location.
	Wildfires and Cattle Health Dr. Gabriele Maier, UC Cooperative Extension specialist for beef cattle herd health and production discusses health issues in cattle after wildfires. While the intended audience is cattle producers in California, the information is relevant to any area that is affected by fires.
	Impact of Fire on Rangelands, What to Expect and What to Do Morgan Doran (UC Cooperative Extension Livestock & Natural Resources Advisor), Tanya Meyer (Yolo County Resource Conservation District Program Manager) and Chris Rose (Solano Resource Conservation District Executive Director) discuss how rangeland ecosystems are very resilient to wildfires and generally do not require post-fire interventions for rehabilitation. They provide information about expected plant community impacts and factors to consider for strategic reseeding of burned sites. This presentation was made in response to the 2020 LNU Fire Complex in Napa, Solano and Yolo counties, but has application to most annual rangelands across California.
	Human-Wildlife Interactions Post Fire Carolyn Whitesell, PhD., with UC Division of Agriculture and Natural Resources, discusses direct and indirect impacts on wildlife and how significant wildfires can be for different wildlife species. She also discusses the likelihood of seeing different species in burned areas and whether or not it’s a good idea to put out water for wildlife after fires.

Poultry

Safety of Backyard Chicken Eggs Post Urban Wildfire Todd Kelman, veterinarian and engineer at the UC Davis School of Veterinary Medicine, discusses the safety of eating eggs from backyard poultry after a wildfire event. This video is intended for anyone whose backyard poultry has been exposed to the ash and smoke of urban wildfire, or whose property may have directly burned in such an event. While much of the focus is on California, the subject matter and the basic considerations for risk assessment and management are applicable worldwide.

1. Pastrana and Low, After the Fire: Backyard Chicken and Egg Safety (2025), UC ANR Fire Network
2. Shapeiro, (2018) Ranch Lessons Learned From Thomas Fire, UC Cooperative Extension