Be cautious but don’t panic about parasites in moose and deer meat when you bring it home

Editor’s note: This story was originally published in October 2023.
It’s not a pleasant thought, but there is always the chance the meat from that moose or deer you harvest this season contains parasites. There can be just a few or, in rare cases, a disturbing infestation of these organisms in the animal’s muscle meat.
In Maine, the most common parasites that may infect moose or deer meat are nasal bots, muscle worms and tapeworm.
Depending on the amount of parasites in the meat — and how strong your stomach is — you can enjoy the meals from a successful hunt.
State biologists say as long as any meat containing parasites is discarded and the remainder is cooked properly, it is perfectly safe to eat. But depending on the specific parasite, care should be taken to make sure the organism does not infect livestock or pets.
“It’s pretty common to see the taenia krabbei worms in moose,” said Lee Kantar, moose biologist with the Maine Department of Inland Fisheries and Wildlife. “A lot of places call it ‘moose measles’ because in the meat it looks like little white, round spots.”
Taenia krabbei is a form of tapeworm specific to moose.
There can be a single taenia worm, or hundreds on any given portion of moose muscle meat, Kantar said.
While it can be stomach churning to see those white bumps in moose meat, humans can’t be infected with either its adult or larval forms. The worm can present a risk to pets — especially dogs.
“You can butcher around the areas with the worm when having the moose processed,” Kantar said. “I also heard of a moose biologist in Vermont who would just flick the eggs or worms out of the meat before cooking it.”
Butchering around a specific area of meat is known as a “wide trim.”
To safely cook moose meat, the U.S. Department of Agriculture recommends preparing it the same way as beef. That means ground meat should be at least 160 degrees Fahrenheit in the center and steaks or roasts to 145 degrees Fahrenheit in the center.
Dogs in particular can be a host animal for the moose tapeworm if they eat uncooked infected meat, so they should never be given raw meat scraps or bones to chew on.
Kantar recommended pet owners keep their animals on a regular deworming schedule.
When it comes to deer meat, it is unlikely parasites will be an issue, said Nathan Bieber, state biologist with the Maine Department of Inland Fisheries and Wildlife.
“We don’t get a lot of issues with [deer] parasites in a year,” Bieber said. “In the very worst cases, we will investigate and if the meat does look bad we will confiscate the deer.”
That is a highly unusual situation in Maine, Bieber said. And in the very few cases it happens, the hunter will be issued another tag to replace that harvested animal.
The parasites you may find in your deer meat are either the nasal bot or a muscle worm confined to the backstrap portion of the carcass.
“The nasal bots are seen occasionally and it’s a grub that comes out of the deer’s nose,” Bieber said. “It is a non-issue for people.”
As for the worms in the backstrap, Bieber said you can either wide trim around any in the butchering process and make sure to cook the remaining meat thoroughly in accordance with USDA beef guidelines.
It’s always a good idea to separate dead things from live things, said Tegwin Taylor, wildlife health biologist with the Maine wildlife department.
“In general, I would say there is a low risk of livestock being exposed to parasites directly from an infected/infested wildlife carcass,” Taylor said. “Most of these parasites require an intermediate host for full development, so there are several steps that have to happen for infection in an end-host to occur.”
Taylor pointed to the parasite that causes brain worm in moose and deer that can infect goats, sheep, alpacas and llamas as examples.
There is no direct path between the parasites and livestock, Taylor said. The organism first has to make a stop in a snail, for example. The snail can pick up parasites as it travels along and a goat or other livestock can become infected when it eats that snail.
Something that should be of no concern are ticks.
“Two or three times a year someone tells me they see ticks inside their deer,” Bieber said. “What they are seeing are bruises that are perfectly normal.”
If a hunter has any doubt about the meat from a harvested animal, Bieber recommends contacting the wildlife department. State biologists can either inspect the meat directly or you can send photos.
“The bottom line,” Bieber said. “Hunt your animal and take home the meat.”