I've come to the conclusion that our worst imaginings of Canadian timber wolves (purposefully introduced to the Lower 48 by do-gooder bureaucrats in 1995) might have been insufficient. To those of us who live in the rural west, these land sharks are well known for their fanged depredations on sheep, cattle, deer, elk, and moose. But their greater menace--at least to humans--might actually be in the form of a tiny tapeworm that they carry: Echinococcus granulosus. This tapeworm was endemic with these wolves, long before they were introduced. Tapeworm cysts have been identified in both Idaho and Montana in recent years, and wolves have been confirmed as definitive hosts and the primary vectors.
Take a few minutes to read this: Two-Thirds of Idaho Wolf Carcasses Examined Have Thousands of Hydatid Disease Tapeworms. Also read this summary and a few of its many linked references.
It bears particular mention that this variety of tapeworm is incurable, except by invasive surgery. (Antiparasitical drugs are ineffective.) And even worse, there is no simple test for infection. Only chest-abdomen scans or whole body scans show "hot spots" where the worms have triggered the formation of cysts. Echinococcosis is not pretty. The Echinococcus granulosus tapeworm cysts are mainly found in the lungs and liver. The tapeworms themselves are just a half inch long, but their cysts are large, ugly, and eventually life threatening, especially in mammals with the longest life spans. (Read: humans.) In some cases they can grow in the heart, the thyroid gland, and although rare, even inside bones and in the brain. I would not like them to start breeding inside my skull. Not good.
The life-cycle Echinococcus eggs and worms is insidious and incremental. The eggs can be viably dormant in the soil for up to 41 months. They can potentially become endemic in a wide variety of mammal populations. Here is just one example: In areas where wolf packs travel, the scat they leave in random locations can be handled by mice and rats that are attracted to the hair that makes up as much as 40% of the scat pellets, by volume. (Rodents actively gather hair, for nesting material.) So they bring the tapeworm eggs home, and are infected. Then the infected rodents get eaten by the local foxes, coyotes, wolves, bobcats, lynx, and mountain lions. And, oh yes, your house cat. Then your sweet little kitty leaves moist deposits in your garden raised beds, or in your child's play sand box. Charming. This is sort of like watching the movie Prometheus, albeit with the critter life cycles in extreme slow motion, and on smaller scale.
I am particularly troubled by the fact that wildlife biologists knew that Canadian timber wolves carried the hydatid tapeworms. (It has been well documented since the 1930s, and was studied in detail in the 1950s.) But because of their enthusiasm, the biologist-activists were silent about it and went ahead and supported the wolf introduction plan. There are some sick puppies out there, and not all of them are canids.
The bottom line: Encourage your state legislators to allow wolf hunting and trapping, to reduce the number of wolf packs. And if you live in wolf country, then DO NOT handle the scat of any predators without wearing gloves and a good quality dust respirator. That includes handling feces from your house cat.
One final parenthetical note: Be on guard for anyone who uses the term "reintroduction" for the introduction Canadian timber wolves in the Lower 48. These wolves were not reintroduced. They are in fact an invasive subspecies. The Canadian timber wolf is a larger subspecies of wolf: Canis lupus occidentalis. The Canadian Timber Wolf (aka Mackenzie River Wolf) can weigh up to 170 pounds and travel up to 70 miles per day. Most of the wolves that originally inhabited the Lower 48 that were extirpated a century ago were the 80 to 110-pound Great Plains Wolf subspecies. (Canis lupus nubilus.) This disparity in part explains the rapid decline of the deer, elk, and moose herds in Idaho and Montana since 2000.