Why use this tool?
In response to a potential Foot and Mouth Disease (FMD) outbreak, implementing robust disease control measures will be vital. An important source of FMD transmission among herds is direct contact due to cattle movement between farms and through auction markets. However, restricting movement can adversely affect business continuity. There is a lack of quantitative data to estimate the risk of cattle movements on disease transmission risk and to distinguish low risk from high-risk movements.
We developed these herd to herd and auction market movement risk models to estimate the risk of movement by FMD infected, but undetected US cattle herds during an FMD outbreak. The models leverage prior knowledge of disease dynamics and simulation model outputs to address movement risk and assist with decisions to allow or restrict cattle movements.
Model descriptions
Single Herd Movement Risk Model
This model is designed to estimate the risk of foot-and-mouth disease (FMD) transmission associated with allowing a cattle shipment from a specific herd, farm, or production facility. It evaluates the likelihood that the herd, farm, or facility has been infected with FMD in the previous twenty-one days and that the infection has gone undetected by the producer. The risk estimate is based on proximity to the nearest FMD-infected premises (IP), the local area assessment of herd to herd FMD transmission risk, the total number of cattle shipments received in the past twenty-one days, the level of implemented enhanced biosecurity measures (as defined by the Secure Beef Supply plan (SBS)) by the producer, and the level of active observational surveillance (AOS) (or daily disease monitoring (DDM)) in place. Results should be interpreted alongside the expertise of state officials, including their knowledge of FMD transmission, familiarity with herd and farm management practices, and professional assessment of the FMD-specific protocols implemented by producers.
Auction Market Model
This model is designed to estimate the risk of foot-and-mouth disease (FMD) transmission associated with allowing cattle shipments through an auction market facility with a defined catchment area. It evaluates the likelihood that a cattle herd within the Auction Market catchment area has been infected with FMD in the previous 21 days, that the infection has gone undetected by the producer, and that the producer ships to the market. Once an infected shipment arrives at the market, sorting and mixing into multiple sale lots and potential transmission of FMD producing new cases is estimated. The risk estimate is based on factors such as Auction Market proximity to the nearest FMD-infected premises, the expected number of cattle shipments to the auction market, the level of infection risk in the catchment area, and the average effectiveness of active observational surveillance (AOS, or daily disease monitoring) by producers. Biosecurity measures (as defined by the Secure Beef Supply plan (SBS)) by the producer, are assumed to be baseline (not enhanced) across all premises in the catchment area. Results should be interpreted alongside the expertise of state and federal officials, including their knowledge of local FMD transmission, familiarity with local herd and herd management practices, and professional assessment of the FMD-specific protocols implemented by producers.
Acknowledgements & Funding
These projects were funded by the USDA National Animal Disease Preparedness and Response Program:
- Grant # AP21VSSP0000C035 - Biosecurity for Cattle Operations: Quantitative Risk Estimation of FMD Transmission Following Cattle Movement
- Grant # AP22VSSP0000C020 - FMD Transmission Risk of Cattle Movements to and from Auction Markets - Quantitative Risk Assessment and Development of an On-line Risk Calculator
Development of this tool by the Center for Outcomes Research and Epidemiology
Further information
If using this tool, please cite:
Andrea L. Dixon, Torre Dunlea, Aidan W. Kerns, and Michael W. Sanderson (2025) Foot-and-Mouth Disease Cattle Movement Risk Models. Shiny application version 1.0.0.
https://andixonksuvet-fmd-shinyapp.share.connect.posit.cloud/.
For questions or more information contact Dr. Mike Sanderson
The total probability of 1 or more infected sale lots for the defined scenario:
Number of Undetected Herds
Number of Undetected Herds Shipping to the Market
Number of Infected Animals Shipped
Number of Infected Sale Lots
- Total Probability of 1 or more infected sale lots at the auction market:
Calculated as: probability of 1 or more undetected herds * probability of undetected herd shipment * probability of 1 or more infected animals shipped * probability of 1 or more infected sale lots.
- Number of Undetected Herds :
The probability distribution of the number of herds in the catchment area that are infected but remain undetected at the end of a 21-day risk period. Data reported here does not include total herds infected, only those that remain undetected and thus at risk for shipping to the market. The data table provides the probability of each number of undetected herds in the catchment area, and the histogram provides the same data visually.
- Number of undetected herds shipping to the market:
The probability distribution of the number of herds in the catchment area that are infected but remain undetected and ship to the market at the end of a 21-day risk period.
So, given that there are:
1 or more undetected herds in the catchment area
Gives the probability distribution of the number of undetected herds that ship to the auction market IF there are 1 or more undetected herds. Accounts for both the number of undetected herds and the probability that a herd ships to the market. The data table provides the probability of each number of undetected herds in the catchment area that ship to the auction market, and the histogram provides the same data visually.
- Number of infected animals shipped:
The probability distribution of the number of cattle shipped to market from herds that are infected but remain undetected and ship to the market at the end of a 21-day risk period.
So, given that there are:
1 or more undetected herds in the catchment area and
1 or more undetected herds ship to the auction market
Gives the probability distribution of the number of infected animals shipped to the auction market IF there are 1 or more undetected herds and 1 or more of the undetected herds ship to the market. Accounts for how many infected (not just clinical, including latent and subclinical infections) cattle are in the shipping herds.
- Number of infected sale lots:
The probability distribution of the number of infected sale lots expected from the shipment of infected cattle to the market.
So, given that there are:
1 or more undetected herds in the catchment area and
1 or more undetected herds ship to the auction market, and
the number of infected animals shipped to the auction market
Gives the probability distribution of the number of infected sale lots resulting from sorting, mixing and transmission at the auction market IF there are 1 or more undetected herds and 1 or more of the undetected herds ship to the market. Accounts for the number of infected cattle shipped sorting into multiple sale lots and transmission resulting in new cases in the market. This number represents the potential number of newly infected herds resulting from market.