The Wild Side: The safety of parasites
Fall is definitely the harvest season, especially for hunters. Black bear and archery deer hunting are open, and small game is in full swing. This means that a lot of my daily work activities will be duly focused on hunting and hunters.
More of my columns are bound to be focused on hunting as well. For example, this past week I had an email question from a conservation warden. I work hard to respond to all the phone calls and emails I get as quickly as I can, but I definitely pay special notice to stuff from wardens. Not because they are cool and carry guns (although that is also true) but because I know that the wardens speak with many more hunters than I do; they are the genuine face of the Department of Natural Resources. The more information I can give them about wildlife, the better equipped they are to help the public, in this case the hunting public, who are our customers during hunting seasons. The warden’s question was valid, one I get several times each year. A hunter harvested a bear, and the guts were nicked in the process. The hunter noticed multiple parasitic worms inside the bear’s intestines. What should the hunter do, and is the bear safe to eat?
Well, to start with, keep in mind that I am neither a medical professional nor an expert in parasitology. I never tell anyone whether or not their animal or bird is safe to eat. Each person needs to consider their level of concern or comfort, and act accordingly. Any living creature (including humans) at any time can have a multitude of creatures living in and on it. Some are helpful, many are relatively benign and some are harmful. Wild animals live in an environment where they are exposed to many kinds of parasites, bacteria and viruses. This is part of the wild organic nature of the animal. If the animal appeared to be relatively healthy, it most likely was functionally fine when harvested. If the animal did not appear alert, or acted sluggish, weak or unstable; if it looked unusually thin and gaunt; if its head was drooping or something else seemed strange or wrong, the animal may have had a more advanced health problem.
If it had visible parasites, cysts or tumors in the muscle tissue, I tell folks to cut them out, being careful to get all of it out, cutting well around it, and avoid puncturing it if at all possible. Personally, if I were gutting a big game animal and saw intestinal parasites, I would not hesitate to process and eat the rest of the bear or deer. It is my understanding that most parasites and their eggs will be killed when meat is thoroughly cooked. If I saw more trouble in the muscle tissue, like pus or bacterial growth, then I might reject that part of the animal, or decide not to use it at all. But that’s me. Also, I don’t eat brains or any other soft tissues. I also don’t eat hearts or livers, so if you’re concerned about liver flukes, you are on your own.
My friend Nancy Businga is a microbiologist with Wildlife Health in Madison. She reminded me that usually the parasites you can see are not the ones you need to be concerned about; it is the ones you can’t see that are a risk. For example: Trichinella will be encysted in the meat of carnivores (and omnivores like bears) and if the meat is not cooked properly, the parasite can infect people (dhs.wisconsin.gov/publications/p4/p42098.pdf). Most wildlife species have internal parasites and live just fine with them. They usually go unnoticed unless someone cuts into the intestines (or makes a gut shot) and looks for them.
So get out and hunt, and enjoy the meat-just prepare it carefully and cook it thoroughly.
Jeremy Holtz is a wildlife biologist with the Wisconsin DNR in Rhinelander, and writes a weekly column in the Star Journal. To contact him, call (715) 365-8999.