Chronic wasting disease and cervid health—2025 highlights
USGS scientists are advancing surveillance, diagnostics, ecological modeling, and decision-support tools to help wildlife managers respond to Chronic Wasting Disease across North America.
What is chronic wasting disease and why is it important to the USGS?
Chronic Wasting Disease (CWD) is a fatal, transmissible neurological disease caused by misfolded prion proteins. It spreads through direct animal contact and the environment. There is no cure or vaccine.
Deer, elk, and moose (cervids) are the main species affected by CWD, and each relies on regular movement to find food, water, and safe places to raise young, often traveling long distances with the change of the seasons.
Some cervid herds travel surprisingly long distances, which makes managing CWD more challenging. For example, certain mule deer in the West migrate more than 200 miles between summer and winter ranges. As animals cross county, state, Tribal, and federal boundaries without showing signs of illness, they can spread the disease into new areas and across entire ecoregions.
The USGS is interested in asking questions related to effective CWD management, which depends on close coordination between agencies that share data, track movements, and respond as CWD shifts across the landscape.
Protecting food, culture, and wildlife
CWD remains one of the most significant and complex wildlife disease challenges facing natural resource managers, intersecting wildlife health, food security, hunting traditions, and rural economies. Healthy cervid populations have supported hunting, wildlife viewing, and local economies for over a century, functioning much like a stable natural resource.
Big‑game hunting is the most common form of hunting in the United States, with 80 percent of hunters participating according to the 2022 USFWS survey. More than 11.5 million big‑game hunters spend an average of 12 days in the field across eight trips each year, underscoring how strongly communities and economies depend on healthy cervid populations.
Additionally, deer, elk, and moose are an important source of protein sustenance for many Native American tribes and serve as a vital part of their culture. The USGS is working with individual Tribal Nations as well as organizations such as the Native American Fish and Wildlife Society to support early detection and an effective response to CWD.
Science to sustain wildlife and the economies that depend on them
Based on congressional direction and administrative priorities, the USGS provides the science needed to help partners safeguard this long‑term sustainability. Through field investigations, laboratory diagnostics, modeling, and decision-support tools, USGS science informs state, Tribal, and federal partners as they work to detect, understand, and manage CWD across North America.
USGS Science Strategy for Chronic Wasting Disease and Cervid Health (2024–2028)
Establishing the President's Make America Healthy Again Commission
IMPROVING THE SAFETY AND SECURITY OF BIOLOGICAL RESEARCH
Why is the USGS still studying CWD in 2025?
CWD can persist in the environment
CWD isn’t spread only by sick animals – it can also linger in the environment. The USGS is studying how infections prions can stick to soil and plants, remaining active long after an infected animal has passed through the area.
Can animal movement predict where CWD will show up next?
Cervids don’t recognize state boundaries and neither do diseases. Using GPS collars and long-term surveillance data, USGS scientists are tracking how deer and elk move across landscapes and how those movements may help CWD spread.
How do scientists find CWD before signs can be visualized?
CWD can be present long before animals show signs of illness. USGS scientists are working to improve early detection tools that can reveal disease presence sooner and across larger areas. Earlier detection means better planning, lower costs, and fewer long-term impacts on wildlife populations and hunting traditions.
Research highlight: Tracking elk to inform management
Elk migration patterns in the Greater Yellowstone and Jackson Hole region illustrate how wildlife management decisions are closely linked to human land use and natural resource needs.
Recent research using GPS-collared “Judas elk” allows managers to differentiate between long-distance migratory elk, which are critical for ecosystem connectivity, and resident elk that rely on agricultural fields and developed landscapes.
These dynamics are especially important in the context of chronic wasting disease, as higher elk densities near human-dominated landscapes can increase the risk of disease transmission and environmental contamination.
Studies like this underscore why understanding and managing the distribution of cervids is not only a wildlife issue but also a natural resource challenge that directly affects human livelihoods, cultural traditions, and sustainable land-use planning.
Three impactful CWD and cervid health science accomplishments in 2025
How can managers detect CWD earlier and more efficiently across large landscapes?
A gloved hand tilts a vial of blood from a healthy white‑tailed deer; it looks ordinary at first glance, but inside are microscopic couriers called exosomes, carrying genetic messages that reveal hidden truths.
In 2025, USGS scientists borrowed a page from human medicine to decode these genetic messages. By sequencing microRNAs tucked inside exosomes, they cataloged more than 130 baseline markers from routine blood draws. This minimally invasive approach could revolutionize wildlife health surveillance, giving managers a way to detect CWD long before symptoms appear and across landscapes as vast as the deer’s migrations carry them.
How do different CWD strains and natural genetic differences in deer affect how quickly the disease spreads through wild populations?
Similar to the flu virus, CWD isn’t one uniform threat; it comes in multiple prion strains, each different, shaping how the disease moves and persists. USGS scientists and partners reviewed current knowledge on the 11 CWD strains. To advance future strain research, they recommended more consistent methods, shared resources, and better collaboration. Improving these areas would help researchers map where strains occur, understand how they change over time, and manage disease risks across North America.
Labs could also benefit from using the same reference CWD samples. These shared samples would serve as benchmarks, helping labs test and identify strains using the same starting material. The USGS is partnering with the USDA to develop the Strain and Genetic Online Tissue Repository (SAGOTR), a web-based platform connecting managers, repositories, and researchers nationwide. SAGOTR allows users to track, request, and share physical CWD samples.
USGS National Wildlife Health Center is working with the state of Wisconsin to investigate how genetic variants in white-tailed deer populations shift during a CWD outbreak and influence disease dynamics.
What are the ecological and population-level consequences of CWD?
CWD affects more than individual deer; it can ripple through entire populations and ecosystems, reshaping herd dynamics and predator-prey relationships.
In 2025, USGS scientists paired long-term monitoring with ecological modeling to uncover these hidden impacts. Subtle declines in survival and reproduction can cascade into population shifts over years, influencing hunting traditions and ecosystem balance. Understanding these ripples helps managers make decisions that safeguard deer, the habitats they use, and the natural resources such as game, vegetation, and water quality that communities rely on.
2025 CWD publication highlights
1. People, partnerships, and CWD:
2. Cervid distribution and management
3. Animal movement and transmission risk
4. Advances in diagnostics and modeling improve early detection and targeted action
A conceptual model describing identified relationships in the decision space framework. The identified themes and subthemes representing the external factors of the decision space framework (Clifford et al. 2022) and how it appears to interact with the ecology of chronic wasting disease and contributes to perceived burnout among study participants.
Predicted effects of male deer harvest on chronic wasting disease (CWD) over time. Harvest pressure, or the proportion of males removed each year, is shown at low (0.2, blue), medium (0.3, grey), and high (0.4, red) levels. Lines show the predicted average CWD prevalence for a herd, with shaded areas representing uncertainty. Herds with higher harvest rates show slower disease growth, suggesting that increasing male harvest could help reduce CWD spread.
USGS scientists are advancing surveillance, diagnostics, ecological modeling, and decision-support tools to help wildlife managers respond to Chronic Wasting Disease across North America.
What is chronic wasting disease and why is it important to the USGS?
Chronic Wasting Disease (CWD) is a fatal, transmissible neurological disease caused by misfolded prion proteins. It spreads through direct animal contact and the environment. There is no cure or vaccine.
Deer, elk, and moose (cervids) are the main species affected by CWD, and each relies on regular movement to find food, water, and safe places to raise young, often traveling long distances with the change of the seasons.
Some cervid herds travel surprisingly long distances, which makes managing CWD more challenging. For example, certain mule deer in the West migrate more than 200 miles between summer and winter ranges. As animals cross county, state, Tribal, and federal boundaries without showing signs of illness, they can spread the disease into new areas and across entire ecoregions.
The USGS is interested in asking questions related to effective CWD management, which depends on close coordination between agencies that share data, track movements, and respond as CWD shifts across the landscape.
Protecting food, culture, and wildlife
CWD remains one of the most significant and complex wildlife disease challenges facing natural resource managers, intersecting wildlife health, food security, hunting traditions, and rural economies. Healthy cervid populations have supported hunting, wildlife viewing, and local economies for over a century, functioning much like a stable natural resource.
Big‑game hunting is the most common form of hunting in the United States, with 80 percent of hunters participating according to the 2022 USFWS survey. More than 11.5 million big‑game hunters spend an average of 12 days in the field across eight trips each year, underscoring how strongly communities and economies depend on healthy cervid populations.
Additionally, deer, elk, and moose are an important source of protein sustenance for many Native American tribes and serve as a vital part of their culture. The USGS is working with individual Tribal Nations as well as organizations such as the Native American Fish and Wildlife Society to support early detection and an effective response to CWD.
Science to sustain wildlife and the economies that depend on them
Based on congressional direction and administrative priorities, the USGS provides the science needed to help partners safeguard this long‑term sustainability. Through field investigations, laboratory diagnostics, modeling, and decision-support tools, USGS science informs state, Tribal, and federal partners as they work to detect, understand, and manage CWD across North America.
USGS Science Strategy for Chronic Wasting Disease and Cervid Health (2024–2028)
Establishing the President's Make America Healthy Again Commission
IMPROVING THE SAFETY AND SECURITY OF BIOLOGICAL RESEARCH
Why is the USGS still studying CWD in 2025?
CWD can persist in the environment
CWD isn’t spread only by sick animals – it can also linger in the environment. The USGS is studying how infections prions can stick to soil and plants, remaining active long after an infected animal has passed through the area.
Can animal movement predict where CWD will show up next?
Cervids don’t recognize state boundaries and neither do diseases. Using GPS collars and long-term surveillance data, USGS scientists are tracking how deer and elk move across landscapes and how those movements may help CWD spread.
How do scientists find CWD before signs can be visualized?
CWD can be present long before animals show signs of illness. USGS scientists are working to improve early detection tools that can reveal disease presence sooner and across larger areas. Earlier detection means better planning, lower costs, and fewer long-term impacts on wildlife populations and hunting traditions.
Research highlight: Tracking elk to inform management
Elk migration patterns in the Greater Yellowstone and Jackson Hole region illustrate how wildlife management decisions are closely linked to human land use and natural resource needs.
Recent research using GPS-collared “Judas elk” allows managers to differentiate between long-distance migratory elk, which are critical for ecosystem connectivity, and resident elk that rely on agricultural fields and developed landscapes.
These dynamics are especially important in the context of chronic wasting disease, as higher elk densities near human-dominated landscapes can increase the risk of disease transmission and environmental contamination.
Studies like this underscore why understanding and managing the distribution of cervids is not only a wildlife issue but also a natural resource challenge that directly affects human livelihoods, cultural traditions, and sustainable land-use planning.
Three impactful CWD and cervid health science accomplishments in 2025
How can managers detect CWD earlier and more efficiently across large landscapes?
A gloved hand tilts a vial of blood from a healthy white‑tailed deer; it looks ordinary at first glance, but inside are microscopic couriers called exosomes, carrying genetic messages that reveal hidden truths.
In 2025, USGS scientists borrowed a page from human medicine to decode these genetic messages. By sequencing microRNAs tucked inside exosomes, they cataloged more than 130 baseline markers from routine blood draws. This minimally invasive approach could revolutionize wildlife health surveillance, giving managers a way to detect CWD long before symptoms appear and across landscapes as vast as the deer’s migrations carry them.
How do different CWD strains and natural genetic differences in deer affect how quickly the disease spreads through wild populations?
Similar to the flu virus, CWD isn’t one uniform threat; it comes in multiple prion strains, each different, shaping how the disease moves and persists. USGS scientists and partners reviewed current knowledge on the 11 CWD strains. To advance future strain research, they recommended more consistent methods, shared resources, and better collaboration. Improving these areas would help researchers map where strains occur, understand how they change over time, and manage disease risks across North America.
Labs could also benefit from using the same reference CWD samples. These shared samples would serve as benchmarks, helping labs test and identify strains using the same starting material. The USGS is partnering with the USDA to develop the Strain and Genetic Online Tissue Repository (SAGOTR), a web-based platform connecting managers, repositories, and researchers nationwide. SAGOTR allows users to track, request, and share physical CWD samples.
USGS National Wildlife Health Center is working with the state of Wisconsin to investigate how genetic variants in white-tailed deer populations shift during a CWD outbreak and influence disease dynamics.
What are the ecological and population-level consequences of CWD?
CWD affects more than individual deer; it can ripple through entire populations and ecosystems, reshaping herd dynamics and predator-prey relationships.
In 2025, USGS scientists paired long-term monitoring with ecological modeling to uncover these hidden impacts. Subtle declines in survival and reproduction can cascade into population shifts over years, influencing hunting traditions and ecosystem balance. Understanding these ripples helps managers make decisions that safeguard deer, the habitats they use, and the natural resources such as game, vegetation, and water quality that communities rely on.
2025 CWD publication highlights
1. People, partnerships, and CWD:
2. Cervid distribution and management
3. Animal movement and transmission risk
4. Advances in diagnostics and modeling improve early detection and targeted action
A conceptual model describing identified relationships in the decision space framework. The identified themes and subthemes representing the external factors of the decision space framework (Clifford et al. 2022) and how it appears to interact with the ecology of chronic wasting disease and contributes to perceived burnout among study participants.
Predicted effects of male deer harvest on chronic wasting disease (CWD) over time. Harvest pressure, or the proportion of males removed each year, is shown at low (0.2, blue), medium (0.3, grey), and high (0.4, red) levels. Lines show the predicted average CWD prevalence for a herd, with shaded areas representing uncertainty. Herds with higher harvest rates show slower disease growth, suggesting that increasing male harvest could help reduce CWD spread.