Deer Diseases

Chronic Wasting Disease (CWD) is a fatal neurological disease that impacts deer, moose, and other members of the deer family (cervids). CWD is classified as a transmissible spongiform encephalopathy, or TSE. Related animal diseases include scrapie in sheep and bovine spongiform encephalopathy (mad cow disease) in cattle.

List and Map of CWD Positive states and provinces    

What are the symptoms of CWD?
Animals may be infected with CWD for many months, even years, before showing symptoms. Symptoms of advanced CWD include emaciation, drooling, holding the head in a lowered position, and disorientation. There is no treatment for CWD and it is ALWAYS FATAL.

How does CWD spread?
CWD is not the result of a virus or bacteria. It is caused by abnormal proteins called prions that attack the brains of infected animals. These infectious prions are most likely transmitted through physical contact (such as nose to nose), through infected feed, or through environmental contamination; for example, through feces or urine. Abnormal prions tend to be most concentrated in nervous system tissue such as the brain or spinal cord or in lymphatic tissue such as lymph nodes.

What are the impacts of CWD?
CWD has the potential to have devastating long-term impacts on deer populations. In some CWD-positive areas of Wyoming and Colorado, prevalence of the disease has exceeded 50% and resulted in population declines. A 2016 study in Wyoming found that CWD-infected deer had a mortality rate 4.5 times greater than uninfected animals. Furthermore, license sales and revenue can decline due to increased concern for the disease and hunter dissatisfaction due to reduced deer densities. States where CWD is found often spend millions of dollars on management actions and increased disease surveillance.

What is NH Fish and Game doing about CWD?

• Don’t use urine-based attractants while hunting. Although there is no direct evidence linking urine-based lures to the spread of CWD there are a number of studies that have shown the prion that causes CWD is present in urine, feces, and saliva of infected animals. Urine for these lures is often collected from captive deer facilities in states where CWD is present. These lures do not undergo any quality control or treatment that might inactivate or kill disease-causing agents, and there is currently no approved testing of commercial lures.
  Most hunters use small amounts of these lures. However, the infective prion is extremely stable and can persist in the environment for years as a source of possible infection. Therefore, there could be cumulative effects due to the continued application of urine-based lures in the environment over time. There are a number of effective synthetic deer lures on the market today which do not pose a risk of spreading disease to New Hampshire’s deer and moose populations. These synthetic deer lures can be used in place of natural urine-based attractants.
• Don't feed deer! The artificially high deer densities associated with feeding create the potential for increased spread and prevalence of CWD, both from infected feed and close contact among individual deer. Deer feeding provides limited benefits to deer but adds significantly to the risk that CWD or other diseases could be spread more quickly and widely.

Is NH Fish and Game conducting surveillance testing for CWD?
NH Fish and Game began a CWD surveillance program for wild deer in the fall of 2002. The Department collects approximately 400 samples from hunter-killed deer annually, which are submitted to a laboratory for testing. To date, CWD has not been detected in any of the samples tested.

Where can I find more information on CWD?
The Chronic Wasting Disease Alliance has developed a website (cwd-info.org) which is acting as a national clearinghouse for the most up-to-date and accurate information on CWD.

Follow NH carcass importation regulations
NH Fish and Game prohibits the importation into the state of hunter-killed cervid carcasses or parts of carcasses from jurisdictions in which CWD has been detected (see map), except for de-boned meat, antlers, antlers attached to skull caps from which all soft tissue has been removed, upper canine teeth (a.k.a. buglers, whistlers or ivories), hides or capes with no part of the head attached, and finished taxidermy mounts.

These regulations are designed to minimize the risk of New Hampshire's deer and moose being exposed to CWD through the importation of an infected animal, or the disposal of tissues from an infected hunter-killed animal. CWD prions are very stable and could easily be spread if diseased deer parts were disposed of in our environment. Hunters can help by sharing this information with other hunters to help ensure New Hampshire remains CWD-free.

If you hunt deer or elk in other states and provinces, particularly those in which CWD has been detected, you should check with their state fish and wildlife agency to see if they have any specific advice to hunters or special regulations.

Epizootic Hemorrhagic Disease (EHD) primarily affects white-tailed deer. EHD is caused by a virus spread by biting midges (“no-see-ums”) and is more common in drought conditions, usually in late summer and early fall. With the onset of colder weather, a hard frost will kill the midges and end the outbreak. EHD is closely related to Bluetongue disease found in livestock. 

Where is EHD Found? 
EHD is found in most of the United States including Vermont, New York, and Connecticut. 

What are the symptoms of EHD?
Deer that are infected with EHD suffer from high fever, dehydration, and internal hemorrhage. They may exhibit frothing at the mouth; swelling of the head, neck, tongue, or eyelids; and may show a lack of fear of people or be reluctant to move.

How does EHD spread?
EHD is caused by a virus spread by biting midges (“no-see-ums”). The midge picks up the virus from the blood of an infected host and transmits the virus by biting another host.  

What are the impacts of EHD? 
EHD may cause localized die-offs of deer although it does not generally have a long-term impact on populations. Deer that die of EHD are often found in or near water and usually within 48 hours of exhibiting symptoms.

How can EHD be managed?
There are no prevention or treatment options for EHD in wild deer populations.

Can EHD infect humans? 
EHD cannot infect humans and does not impact the safety of deer meat. However, deer that appear sick or are in poor condition should not be consumed because they could have secondary infections that may make the meat unfit for consumption.

What Can You Do? 
If you see sick or dead deer that display any of the symptoms described above, please contact the NH Fish and Game Wildlife Division at (603)-271-2461.

Recent studies have shown that white-tailed deer can be infected with SARS-CoV-2, the virus that causes COVID-19 in humans

Emerging Research:

• Testing in deer across multiple states and Canadian provinces has shown that significant proportions of deer populations may be infected but infection rates vary geographically and over time. For example, 35% of deer samples collected in Ohio in early 2021 tested positive while just 6% of deer tested in Ontario in late 2021 were infected. 
• Research suggests that wild deer likely contracted the virus from humans through multiple human-to-deer “spillover” events and that transmission is then sustained within the deer population. The precise route of human-to-deer transmission is not known.
• New Hampshire Fish and Game biologists, in conjunction with USDA Wildlife Services, collected blood samples and nasal swabs from harvested deer during the 2022 hunting season for SARS-CoV-2 testing. Four percent (4%) of deer showed evidence of previous exposure to the SARS-CoV-2 virus and 0% showed signs of active infection.
• Captive studies suggest that deer do not show symptoms when infected with the SARS-CoV-2 virus.

Recommendations: 

There is no evidence that deer are playing a significant role in the spread of COVID-19 among people, and the risk of contracting the virus from wildlife is considered low. There is also no evidence to suggest that a person could contract COVID-19 from eating game meat. However, the public should observe the following best practices to protect themselves from wildlife diseases:

• Remember to give wildlife space and observe them from a distance.
• If you find a wild animal that is sick, injured, or in distress, contact NHFG.
• Hunters should take basic precautions to protect themselves from disease when field dressing or processing game.