Reduce your risk of contracting diseases from wild game by learning about common zoonotic diseases in humans, how to prevent them, CWD deer symptoms, leptospirosis symptoms in humans, and baylisascaris in humans to watch for.
Hunting is a popular pastime. While hunters are aware of the dangers associated with the pursuit of wild game, an unseen danger can potentially lurk within every rabbit, squirrel, or deer you harvest: disease-causing microbes. Animals can pass on these harmful microbes – which can include viruses, bacteria, parasites, and fungi – to humans. Some microbes may not be deleterious to their animal hosts, but they can turn harmful in humans, causing everything from mild sickness to death. Let’s take a look at some zoonotic diseases you might encounter in the wild and how to avoid or mitigate your exposure.
Diseases Carried by Ticks
By far, the most common diseases that affect hunters and hikers are those transmitted by ticks. This pest is responsible for a host of potential threats to anyone venturing outdoors.  Lyme disease, anaplasmosis, and Rocky Mountain Spotted Fever  are all transmitted through tick bites.
Prevention. Be aware of your surroundings, wear proper clothing, and use insect repellent. Most commercially available repellents contain DEET as an active ingredient, but other safe and effective repellents are available. Use what’s best for you.
Most ticks will attach to your feet and lower legs, though you may find them higher up on your body. Wear light-colored clothing, as this makes the ticks easier to spot. Don’t wear sandals or flip-flops when walking through tall grass. Tuck your pant legs into your boots and socks, and tuck your long-sleeved shirt into your pants.
As soon as you get back home, strip down and shake out your clothing before going inside, and then bag your clothes. Wash off any loose ticks with a shower, and then examine yourself carefully for ticks that may have taken hold. Pay close attention to your underarms, groin, hair, hairline, belly button, ears, and behind your knees. Lastly, wash your clothes, and then dry them on hot for at least 10 minutes.
Take it from someone who knows: All of these steps are no guarantee. Even the most cautious of us will get bitten. When you find a tick on your body, remove it as soon as possible to help reduce your risk. Just because you’ve been bitten by a tick doesn’t mean you’ll necessarily get a tick-borne disease. Your best bet is to keep an eye on the bite and be aware of any potential symptoms appearing. If possible, freeze the tick or preserve it in rubbing alcohol for further identification.
Lyme Disease
The most common tick-transmitted illness is Lyme disease, which is caused primarily by the Borrelia burgdorferi bacteria and the B. mayonii bacteria to a much lesser extent. Blacklegged ticks, or “deer ticks,” are known to carry Borrelia bacteria, and they’re found throughout the United States, although they’re most common in the Midwest, Northeast, and mid-Atlantic areas. On the Pacific Coast, the western blacklegged tick can transmit the disease.
Symptoms. The following symptoms are the first stage of the disease and will usually occur 3 to 30 days after being bitten. A rash is a common first sign for 70 to 80 percent of people who’ve contracted the disease. Often called a “bull’s-eye rash,” the rash will form a ring spanning 12 inches or more in diameter around the bite site; however, the ring won’t appear in some people. Other early symptoms include swollen lymph nodes, fever, headache, extreme fatigue, joint stiffness, and muscle aches.
If left untreated, Lyme disease can result in more severe symptoms, including facial palsy, arthritis, nerve pain, and brain and spinal-cord inflammation. The good news is that the disease can be treated; the earlier, the better.
Anaplasmosis
Like Lyme disease, anaplasmosis is transmitted by blacklegged and western blacklegged ticks. Anaplasmosis is caused by the Anaplasma phagocytophilum bacterium, and it can be treated in its early stages with antibiotics. Risk factors for a severe presentation of anaplasmosis include a compromised immune system, delaying treatment, or being older than 50.
Symptoms. Symptoms will start out very mild and flu-like, and, according to the Centers for Disease Control and Prevention (CDC), they’ll often appear 1 to 2 weeks after the person has been bitten. Symptoms include nausea, vomiting, fever, chills, severe headache, and muscle ache. Late-stage anaplasmosis can lead to respiratory failure, organ failure, and death.
Rocky Mountain Spotted Fever
Rocky Mountain Spotted Fever (RMSF) is caused by the Rickettsia rickettsii bacteria, and it’s transmitted most commonly by the Rocky Mountain wood tick, the American dog tick, the lone star tick, and the brown dog tick. Despite its name, cases of RMSF have been confirmed throughout the U.S., Canada, Mexico, and South and Central America.
Symptoms. Fever, headache, nausea, vomiting, and muscle pain can begin 5 to 10 days after being bitten. A rash may also be present. As the disease progresses, the infected person may experience confusion, shortness of breath, seizures, and numbness. If you experience any of these symptoms and have been in an area where you may have had contact with ticks, seek medical advice. Without treatment, RMSF has a 20 to 30 percent fatality rate.
Chronic Wasting Disease
Chronic Wasting Disease (CWD) affects all members of the deer family (deer, elk, moose, etc.). Caused by misfolded proteins, or “prions,” CWD affects deer in the U.S., Canada, northern Europe, and some parts of Asia. CWD deer symptoms and other animals are a drastic loss of weight, stumbling, drooling, no fear of people, and other neurological symptoms. CWD is transmitted through bodily fluids – such as feces, saliva, blood, and urine – and these bodily fluids can further contaminate water, soil, and food and lead to indirect transmission. CWD is always fatal in afflicted animals.
In the late 1960s, CWD was first observed in captive deer and roughly 20 years later in wild deer, though CWD isn’t widespread in wild-deer populations. CWD has been found in 34 states, with the highest concentrations in Wyoming, Wisconsin, Montana, Kansas, and Colorado. Currently, there’s no evidence CWD can be transmitted to people.
Can You Eat a Deer with Chronic Wasting Disease?
Avoid eating infected deer, elk, or moose meat or coming into contact with an infected animal’s bodily fluids. If you’re a deer hunter, take the following precautions to protect yourself. First, check with state health guidelines regarding the deer in your area. Second, don’t shoot, handle, or eat the meat of any deer that looks sick, acts strangely, or is found already dead. Third, when field dressing your catch, wear latex or rubber gloves, minimize how much you handle organs, and don’t use household knives. Last, test the meat for CWD before eating it.
Leptospirosis
If you’re a small-game hunter, you might be familiar with, or have at least heard of, leptospirosis. Leptospirosis is caused by the bacteria Leptospira. It’s transmitted from contact with the urine or other bodily fluids of many animals, but it’s most common in wild hogs, rabbits, and squirrels. This bacteria enters the body through cuts and rashes in the skin or through the eyes, mouth, and nose. Infection can also occur after exposure to contaminated water (think floods) or by drinking contaminated water.
Leptospirosis Symptoms in Humans
Leptospirosis symptoms include high fever, headache, chills, muscle aches, vomiting, jaundice, red eyes, abdominal pain, diarrhea, and rash. Some people may get all of them, while others may only develop a few. An infected person may take anywhere from 2 days to 4 weeks for symptoms to start showing up. If left untreated, leptospirosis can lead to kidney failure, liver failure, meningitis, or death.
The good news is that this disease can be treated, and the sooner the better. Because these symptoms can often be associated with other illnesses, leptospirosis can be hard to diagnose. Your best bet would be to get some blood work done, so provide as much information as possible to your doctor. With treatment, duration of the illness could be from 3 days to 3 weeks, but it could last several months without treatment.
Baylisascaris or Raccoon Fever
Baylisascaris, or “raccoon fever,” is caused by the Baylisascaris procyonis roundworm, which is found in the intestines of raccoons and by the B. columnaris roundworm in skunks. Infections are rare but can become deadly, so take caution when dealing with raccoons or skunks.
Symptoms of Baylisascaris in Humans
As baylisascaris is caused by a parasite, it may show different symptoms than other diseases previously covered. Symptoms begin in 1 to 4 weeks, and they include nausea, fatigue, liver enlargement, loss of coordination, lack of attention to other people, loss of muscle control, blindness, and coma. Diagnosis of baylisascaris is often made by exclusion, given that there are no widely available tests for it, making it difficult to detect. No currently available drug treatments are completely effective in people.
Prevention. As with most diseases, prevention is your best protection. Wear protective clothing, such as rubber boots and latex or rubber gloves, when dealing with raccoons. Thoroughly clean your hands with soap and running water often, and wash your potentially contaminated clothing in hot water. During and after exposure, keep your hands away from your eyes, nose, and mouth.
Rabies
Perhaps no other zoonotic disease gets more hype than rabies – and for good reason. Rabies is always fatal if left untreated. While we associate rabies with wild animals, such as skunks, foxes, bats, and raccoons, all mammals – including humans – can get and transmit rabies. Unlike the other diseases covered here, rabies is caused by viruses from the genus Lyssavirus, and it can be transmitted through direct contact with saliva, brain tissue, or spinal fluid from an infected animal. It enters your system through broken skin or the mucous membranes of the nose, eyes, and mouth. According to the CDC, most human exposure to rabies comes from getting bitten by an infected animal.
Symptoms. Like with all viruses, rabies has an incubation period that could last for weeks or even months. It all depends on the type of rabies virus, where the bite occurred on the body, or any natural immunity the person may have. The virus has to travel to the brain before symptoms start to show. Symptoms start out mild, almost flu-like, but increase from there. Early signs are cerebral dysfunction, anxiety, confusion, and agitation, while advanced symptoms are delirium, abnormal behavior, and hallucinations. Early treatment is a must: Once the virus reaches the advanced stages, the infected person will die.
Prevention. Like with everything else, prevention is key. Stay away from wildlife. If you see wildlife acting abnormally, contact the proper authorities. If you’re a hunter or trapper, avoid contact with the brain or spinal fluid of the animal you’re processing, and always wear latex or rubber gloves. During and after processing, don’t touch your eyes, nose, or mouth, and thoroughly wash your hands often.
We all share “occupational hazards” when outside. While I’ve spent my life outdoors, I’ve been fortunate to have never contracted any of the diseases mentioned. When you venture out, don’t let your guard down, and use common sense. Take preventive measures to protect yourself, your pets, and your family. As the saying goes, “An ounce of prevention is worth a pound of cure.”
Dana Benner has been writing about all aspects of the outdoors for 35 years, with his work appearing in numerous publications, including Mother Earth News, Countryside and Small Stock Journal, Backwoods Survival Guide, and others.