What happens if you eat deer with CWD?

Quick Answer

Chronic wasting disease (CWD) is a fatal neurological illness occurring in deer, elk, reindeer, sika deer and moose. Consuming meat from CWD-infected animals is not recommended as CWD prions (misfolded proteins) accumulate in tissues throughout the body including muscle meat. While the risk of transmission to humans is considered low, it may cause a variant Creutzfeldt-Jakob Disease (vCJD), which is fatal.

What is Chronic Wasting Disease (CWD)?

Chronic wasting disease (CWD) is a fatal, neurological illness occurring in North American deer, elk, reindeer, sika deer and moose populations. It was first observed as a wasting syndrome in the late 1960s in mule deer in Colorado and in captive deer herds in Colorado and Wyoming between 1969 and 1981.

CWD belongs to the group of diseases called transmissible spongiform encephalopathies (TSEs) or prion diseases. Other TSEs include scrapie in sheep, bovine spongiform encephalopathy (BSE) or ‘mad cow disease’ in cattle, Creutzfeldt-Jakob disease (CJD) in humans and feline spongiform encephalopathy in cats.

The disease progressively attacks the brain of infected deer and elk resulting in altered behavior, progressive weight loss, excessive salivation, loss of body condition, and death. The name “wasting disease” comes from the progressive loss of weight and body condition in affected animals. The incubation period from infection to onset of clinical signs ranges from 16 months to 36 months or longer. Once infected, the animal progressively declines until death.


CWD is caused by prions, which are abnormally folded proteins capable of transmitting their misfolded shape onto normal variants of the same protein. The prions accumulate in the central nervous system and lymphoid tissues ultimately resulting in microscopic holes in the brain giving it a ‘spongy’ appearance – thus the name transmissible spongiform encephalopathies.

The prions that cause CWD are highly resistant and accumulate in the environment persisting for years. Deer and elk become infected through direct contact with bodily fluids from infected deer or contact with a highly contaminated environment. The prions accumulate throughout the body of infected deer but are concentrated in the central nervous system and lymphoid tissues.

CWD is contagious and spreads slowly within infected deer and elk populations and to new areas. Management strategies focus on controlling the spread of CWD. There is no treatment or vaccine to control the disease.


CWD occurs in free-ranging and captive deer, elk, reindeer, sika deer and moose populations in the United States, Canada, Norway, Finland and South Korea. In North America, CWD is endemic in areas of Colorado, Wyoming, South Dakota, Nebraska, Montana, Wisconsin, Minnesota, Missouri, Illinois, Utah, New Mexico, New York, West Virginia, Virginia, Maryland, Pennsylvania, Michigan, Kansas, Oklahoma, Iowa, Texas, Arkansas, Alberta, and Saskatchewan. The infection rate in some wild deer populations is estimated to be as high as 30-50%.


CWD spreads between deer and elk through direct contact and indirectly through environmental contamination. The prions are shed in saliva, urine, blood, soft-antler material, feces and carcasses. The prions persist in the environment and soil binding tightly to clay components. Deer and elk contract CWD by consuming infected material through grazing or nuzzling infected environments. The disease spreads slowly through the population with more deer becoming infected over time.

CWD transmission is very efficient within deer populations with a higher attack rate in males related to their behaviors. Males have a higher incidence rate as they disperse from core areas during the breeding season. Yearling deer show higher rates as they have more direct contact through grouping behavior. The incidence rate is lower in older deer likely due to death from the disease before old age.

Human Risk

While there have been no reported cases of CWD infection in humans, consumption of meat from infected deer and elk is not recommended. The Center for Disease Control (CDC) has issued precautions related to handling and consumption of deer and elk from known CWD-affected areas.

CWD prions accumulate in the muscle and other tissues of infected deer. So, consuming infected venison presents a risk for human transmission. There is an ongoing study assessing people who have consumed meat from CWD-infected deer and elk to determine long-term effects.

If CWD prions were to infect humans, the disease caused would likely resemble Creutzfeldt-Jakob disease (CJD). There are different variations of CJD, which are fatal neurodegenerative prion diseases in humans. Consuming CWD infected meat may cause a variant CJD (vCJD), which occurred in humans that consumed meat products contaminated with mad cow disease.

Signs of CWD

In the early stages, infected deer and elk display subtle changes in behavior and appearance. In later stages, signs become more pronounced and reflect the damage occurring in the brain. Changes seen with CWD infection include:

  • Gradual weight loss and muscle wasting leading to emaciation
  • Excessive salivation
  • Loss of appetite
  • Listlessness, lack of alertness
  • Isolation from the herd
  • Increased drinking and urination
  • Grinding teeth excessively
  • Drooping head and ears
  • Lack of coordination, stumbling, trembling
  • Drooling
  • Difficulty swallowing
  • Excessive rolling or flicking of the ears

These signs progress gradually over weeks to months with increasing severity culminating in death. Infected animals may live for several months displaying worsening clinical signs before death occurs. The signs reflect the accumulating damage in the brain as the infection progresses. Weight loss and wasting are very characteristic despite retention of appetite early in the course of disease.

Confirming CWD

There is no live animal test for CWD. The disease can only be confirmed by examining the brain or lymph tissues after death. The following tests are used:


This test detects prion proteins in brain or lymphoid tissues by using prion protein specific antibodies with detection by microscopy. It is considered the gold standard test and can differentiate between CWD and other diseases.

Western blot

The Western blot detects prion proteins on a nitrocellulose membrane using protein-specific antibodies. It serves to confirm Immunohistochemistry results.


This enzyme-linked immunosorbent assay also detects prion proteins using antibodies and color change for detection. It is used primarily for testing deer and elk harvested in CWD endemic areas.

What happens if you eat CWD infected deer?

While there are no confirmed cases of humans contracting CWD, consuming venison from CWD-infected deer and elk is considered inadvisable based on potential risks. Here is what the science tells us so far:

CWD prions accumulate in deer tissues

Prions that cause CWD accumulate throughout an infected deer’s body, including muscle and organ meats like the heart. Prions concentrate mainly in the central nervous system and lymphoid tissues. In one study, CWD prions were found in the muscles of over 80% of deer naturally infected with CWD.

CWD prions can infect humans

Laboratory studies indicate that CWD prions can infect non-human primates that eat infected meat. Squirrel monkeys developed variant CJD (vCJD) type symptoms after consuming infected deer and elk meat or after injection with CWD prions. This indicates the potential for cross-species infection.

Eating CWD venison could cause human prion disease

While there is no direct evidence yet, consuming CWD contaminated venison could potentially cause Creutzfeldt-Jakob disease (CJD) in humans. People could acquire a variant CJD (vCJD) from eating infected deer or elk meat. Consuming meat contaminated with mad cow disease prions has caused vCJD in humans.

No direct proof CWD infects humans

There have been no reported cases of human illness due to CWD exposure as of 2023. However, the Centers for Disease Control (CDC) recommends not consuming meat from CWD-infected deer and elk due to potential risks. Ongoing National Prion Disease Pathology Surveillance Center studies are monitoring high-risk people who have consumed venison from CWD-positive areas to identify any illness linked to CWD exposure.

Fatal neurodegenerative disease if infected

If CWD prions were to infect humans after eating contaminated meat, the disease caused would most likely resemble Creutzfeldt-Jakob disease (CJD). CJD is a fatal neurodegenerative brain disorder in humans caused by prions. Different variations of CJD exist depending on the exposure source. Variant CJD (vCJD) occurred in humans that ate meat contaminated with ‘mad cow disease’ prions.

Symptoms of CJD

The human prion diseases linked to consumption of contaminated meats produce a disease similar to Creutzfeldt-Jakob disease (CJD). The incubation period before symptoms appear is long, on the order of years or decades. Initial symptoms include:

  • Memory problems and confusion
  • Anxiety, depression, mood swings
  • Muscle incoordination, involuntary movements
  • Vision problems, hallucinations, delusions
  • Difficulty speaking and communicating

As damage progresses, mental impairment increases along with rapidly progressing dementia. Jerking movements, rigidity, and loss of balance also occur. The disease culminates in immobility and coma. Death usually occurs within one year of symptom onset. There is no treatment other than palliative care.

Risk of Exposure

The risk of human exposure to CWD occurs through:

Consuming infected deer and elk meat

Eating meat from CWD infected animals. Venison from hunted deer, elk, and other cervids could potentially be contaminated with CWD prions.

Contact with tissues during processing

Handling tissues like the brain, spinal cord, lymph nodes, spleen, and nerves during the processing of deer and elk carcasses. Contaminated materials on knives and surfaces also pose a risk.

Contact with other high-risk materials

Coming in contact with materials potentially high in CWD prions like taxidermy mounts, antler products, and urine based deer attractants. Deer urine products may originate from farmed deer infected with CWD.

Environmental exposure

Touching soil, plants, and surfaces potentially contaminated with prions from deer saliva, urine, feces etc. in areas with high infection rates in deer populations. CWD prions can persist in the environment for years.

Reducing CWD Exposure Risk

Steps to reduce potential CWD exposure when handling and consuming deer, elk, and moose harvested from CWD areas:

  • Do not shoot or handle any animal appearing sick or abnormal.
  • Wear latex or rubber gloves when field dressing carcasses.
  • Minimize handling brain, spinal cord, eyes, spleen, and lymph nodes.
  • Avoid using kitchen knives or utensils on meat used on carcass and CNS tissues.
  • Wash hands and disinfect surfaces after processing meat.
  • Consider not eating meat from CWD endemic areas.
  • If cooking venison, use recommended temperature-time guidelines to destroy CWD prions.
  • Avoid high-risk tissues like brain, spinal cord, spleen, lymph nodes.
  • Avoid use of products like natural deer urine as attractants.

Testing harvested deer from CWD areas provides information about CWD risks in the region and the potential for human exposure. Submitting samples for CWD testing is recommended whenever possible.

Is it safe to eat CWD venison?

While no human CWD infections have been reported to date, health agencies still recommend caution regarding consuming venison from CWD-infected deer and elk due to potential risks:

CDC recommendations

The U.S. Center for Disease Control (CDC) recommends against consuming meat from CWD-positive animals. Hunters should have deer and elk tested before eating meat from areas where CWD occurs.

WHO advice

The World Health Organization advises against consuming CWD positive venison based on evidence that CWD prions can infect humans.

Potential for prion disease

Studies indicate the potential for human transmission is quite plausible. Eating CWD contaminated meat could potentially cause a prion disease like Creutzfeldt-Jakob disease (CJD).

Lack of direct evidence

The risks are still theoretical as there’s no direct proof CWD prions have infected humans yet. However, health agencies follow the precautionary principle to protect public health due to potential consequences.

Meat preparation guidelines

Proper preparation and cooking of venison may reduce risks, but experts still advise avoiding meat from known infected or potentially infected deer and elk.

Cooking meat to destroy CWD prions

CWD prions are extremely resistant to heat and disinfectants. However, some sterilization procedures may reduce infectious prion loads in contaminated meat:

High heat over 30 minutes

Cooking potentially contaminated meat to an internal temperature of 165°F (74°C) for at least 30 minutes reduces prion loads by >99.99% based on lab studies with CWD prions.

Pressure cooking

Pressure cooking venison to 250°F (121°C) for 30 minutes under 3 atmospheres pressure (15 psi) may also effectively destroy prions based on prion deactivation data.

Alkaline hydrolysis

Digesting tissues using alkaline hydrolysis with 1N sodium hydroxide for 2 hours solubilizes prions, reducing infectious titers by >5 logs.

Chlorine dioxide

Treating meat with 5000 ppm chlorine dioxide solution for 2 hours reduces prion loads by about 99%. However, residual PrP may remain.

Recommendations for venison

The CDC recommends cooking all wild game meat thoroughly to 165°F (74°C) as measured by a meat thermometer to destroy potential pathogens and parasites.

CWD prevention in deer populations

Strategies used by wildlife agencies to prevent CWD spread and reduce local prevalence in wild deer include:

Surveillance and testing

Monitoring deer populations in CWD unaffected areas through targeted surveillance to identify new outbreaks early and enable rapid response.

Carcass regulations

Bans on transporting intact deer carcasses out of CWD endemic zones to minimize spread to new regions.

Selective culling

Sharply reducing local deer densities through extensive culling in CWD hotspots can slow or eliminate CWD regionally when implemented early.

Ban supplemental feeding

Prohibiting artificial feeding like deer bait concentrates deer increasing direct contact and CWD transmission.

Exclusion fencing

Fencing to prevent wild deer access to captive herds and artificial deer congregations avoids CWD transfer.

Quarantine captive deer

Mandatory CWD testing in captive deer with multi-year quarantine requirements has reduced CWD occurrences in farmed cervid facilities.


Chronic wasting disease (CWD) is an invariably fatal neurological disease occurring in deer populations in North America. Consuming meat from CWD infected deer and elk is strongly discouraged due to potential prion disease risks to humans. There is substantial circumstantial evidence that CWD prions can infect humans, likely resulting in a Creutzfeldt-Jakob disease (CJD) like neurodegenerative disorder which is fatal. While no direct cases have been reported yet, health agencies follow the precautionary principle and recommend avoiding meat from CWD infected animals due to potential consequences. Properly cooking meat to recommended temperatures may lower, but not eliminate risks. Ongoing studies are monitoring high-risk individuals that have consumed CWD venison to detect potential CWD transmission to humans. Strategies for managing CWD in wild deer populations focus on surveillance, testing, carcass regulations, culling, movement restrictions, and herd management practices. However, once established locally, CWD is extremely difficult to eliminate from wild deer and proves persistent.

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