Intestinal Parasites - Tapeworms, Roundworms & Hook Worms

WARNING: Some images, gifs and videos below may be difficult for some viewers to see/watch!

Intestinal Parasites:[]

What type of parasites do bears have?[]

Bears are hosts of many internal (over 50 types of worms in their intestines and lungs) and external (black flies, mosquitoes, midges) parasites. Each can potentially weaken a bear, which may lead to injury or death by other causes. At Brooks, especially toward the end of summer and into fall, bears sometimes shed a type of tapeworm, commonly called the broad fish tape worm. It can sometimes be seen trailing behind them. Bears can become infected by the tapeworm from eating raw salmon.

Parasites in Alaska Brown Bears National Park Service Article:[]

Gates of the Arctic National Park, Katmai National Park & Preserve, Lake Clark National Park & Preserve

A team of researchers from numerous universities and state and federal agencies documented the prevalence of parasites in brown bears that could potentially affect wildlife health throughout Alaska. Using samples collected from the temperate rainforests of southeast Alaska to tundra above the Arctic Circle, scientists looked for a diverse array of parasites including those that may infect the intestines, blood, or skin of affected bears. Scientists found parasites to be relatively uncommon, which may be due, in part, to the remote, wild, and healthy populations sampled. Intestinal parasites, including hook worms, roundworms, and tapeworms, were most commonly detected in Alaska brown bears. Scientists also found evidence for exposure to mites affecting the skin. Researchers did not find evidence for blood parasites among the samples tested. Given that parasites can influence the health of individuals, as well populations, this study provides important contemporary baseline for researchers to assess changes through time and relative to ecological changes.

INTESTINAL PARASITES NPS PHOTO — Parasites are relatively uncommon in Alaska's brown bears, showing populations to be wild and healthy. Intestinal worms were the most common parasites found. NPS photograph

Survey for Selected Parasites in Alaska Brown Bears (Ursus arctos)

Abstract

To assess infection with or exposure to endo- and ectoparasites in Alaska brown bears (Ursus arctos), blood and fecal samples were collected during 2013–17 from five locations: Gates of the Arctic National Park and Preserve; Katmai National Park; Lake Clark National Park and Preserve; Yakutat Forelands; and Kodiak Island. Standard fecal centrifugal flotation was used to screen for gastrointestinal parasites, molecular techniques were used to test blood for the presence of Bartonella and Babesia spp., and an ELISA was used to detect antibodies to Sarcoptes scabiei, a species of mite recently associated with mange in American black bears (Ursus americanus). From fecal flotations (n=160), we identified the following helminth eggs: Uncinaria sp. (n=16, 10.0%), Baylisascaris sp. (n=5, 3.1%), Dibothriocephalus sp. (n=2, 1.2%), and taeniid-type eggs (n=1, 0.6%). Molecular screening for intraerythrocytic parasites (Babesia spp.) and intracellular bacteria (Bartonella spp.) was negative for all bears tested. We detected antibodies to S. scabiei in six of 59 (10.2%) individuals. The relatively low level of parasite detection in this study meets expectations for brown bear populations living in large, relatively undisturbed habitats near the northern edge of the range. These results provide a contemporary understanding of parasites in Alaska brown bears and establish baseline levels of parasite presence to monitor for changes over time and relative to ecologic alterations.

Haynes, E., S. Coker, M. J. Yabsley, K. D. Niedrighaus, A. M. Ramey, G. G. Verocai, G. V. Hilderbrand, K. Joly, D. D. Gustine, B. Mangipane, W. B. Leacock, A. P. Crupi, and C. A. Cleveland. 2023. Survey for selected parasites in Alaska brown bears (Ursus arctos). Journal of Wildlife Diseases 59 (1): 186-191.

DOI: 10.7589/JWD-D-22-00070.

Survey for Selected Parasites in Alaska Brown Bears (Ursus Arctos)[]

Table 1 & Table 2:

Tapeworm Tidbits:[]

The Disturbingly Long Tapeworms of Alaskan Bears:[]

"The tapeworm’s eggs are in Alaskan rivers, where they are eaten by crustaceans, which are eaten by salmon, which are eaten by bears. The tapeworm lodges in the bear’s digestive tract, where it lives out its days."
"The adult tapeworm gets its nourishment from what the bear eats. "
"A tapeworm living inside a bear can reach lengths of 30 feet or more. "
"Viewers of live cam feed at Katmai National Park occasionally note giant worms dangling from the famous brown bears."

How the sushi boom is fueling tapeworm infections:[]

"The tapeworm is a monstrous and impressive creation. It has a segmented body, with male and female reproductive organs in each segment, so it is capable of self-fertilization. It does not have a head as such – its “head” is only useful for holding on to its host’s gut, rather than for “eating” (it absorbs nutrients through its skin)."

Brooks River Bears Observed with Tapeworms:[]

WARNING: THE FOLLOWING PHOTOGRAPH MAY BE DIFFICULT FOR SOME TO VIEW!

225: September 24, 2022 NPS photograph by Ranger Tammy Carmack

225 NPS PHOTO 2022.09.24 w HUGE TAPEWORM RANGER TAMMY CARMACK — 225 September 24, 2022 with a HUGE tapeworm NPS photograph by Ranger Tammy Carmack

308:[]

308: September 3, 2022 video by Brianna B:

Katmai_Bears_(9-03-22)_-_708s_from_Riverwatch_platform — Katmai Bears (9-03-22) - 708s from Riverwatch platform

video by Brianna B

344:[]

344: October 19, 2020 video by mckate:

19_Oct_2020-_344_in_the_Riffles_(explore.org) — 19 Oct 2020- 344 in the Riffles (explore.org)

video by mckate

384:[]

384: September 26, 2022 384 Itzy LO 335's video:

284s_Bunny_BF_09-26-22_explore.org — 284s Bunny BF 09-26-22 explore.org

384 video by Itzy LO 335

409 Beadnose & Offspring:[]

409 Beadnose's 2017 Cub: video by Travel Guide Book

Travel Guide Book shares the following information with their Facebook video of 409's Beadnose's 2017 Cub with the tapeworm:

"...Towards the end of summer and into fall, bears sometimes shed a type of tapeworm, commonly called the broad fish tapeworm. Bears become infected by the tapeworm from eating raw salmon. The physical effect of bears harboring tapeworm parasites is insignificant to the bear's health. It is thought wild bears may expel adult egg-laying worms prior to denning as they have fewer tapeworms in spring compared to autumn. However when they start eating raw salmon again, high tapeworm levels return. Some bears have been seen with tape worms that trail up to 10 feet or more. Fish tapeworm naturally moves from larval stages in fish to adult stages in bears (or sea mammals). The large mammals then excrete the eggs back into the water to start the process all over again. ..."