PARASITES OF NEWFOUNDLAND CARIBOU, RANGIFER TARANDUS CARIBOU: AN INTRODUCTION TO ELAPHOSTRONGYLUS RANGIFERI AND ITS EFFECTS

Mammalogy 4630

March 7th, 2011

Kendra Dawe

Caribou in Newfoundland

Rangifer tarandus caribou is the woodland caribou, and is native to the province

There are currently 9 herds on the island

Like nearly all wild animals, R. tarandus caribou suffer from a variety of parasites including: Fly infestations: Warble Fly

and Throat Bots Tapeworm Cysts: found in the

liver, lungs and muscle tissue Nematodes: Elaphostrongylus

rangiferi causes CSE affecting the Central Nervous System and muscle tissue

Figure 1: Male woodland caribou, Rangifer tarandus caribou

A Brief History

Caribou have always played an important role to the people inhabiting the island

In late 19th Century caribou populations began to dwindle quickly due to over hunting

Solution: 1908, brought 300 reindeer from Norway to St. Anthony to supplement the population

1950’s first record of illness in animals 1976: major outbreak and illness was associated

with E. rangiferi 1990’s: E. rangiferi infected the last herds that

were previously uninfected, reaching the Avalon

Distribution of Herds

St. Anthony

Northern Peninsula

Gaff Topsails

Middle Range

Cape Shore

Avalon

Merasheen Island

Bay de Verde

Figure 2: Caribou herd distribution in Newfoundland

E. rangiferi and CSE

Illness caused by E. rangiferi is known as Cerebrospinal Elaphostrongylosis, CSE

CSE causes changes in behaviour such as: Self-isolation Staying in one location for long periods of time Appearance of being disoriented Walking in circles Overly tame towards humans

Also can cause severe muscle and nerve damage: Weakness in hindquarters Abnormal posture and gait

CSE in Caribou

Figure 3: A caribou suffering from CSE. Note the weak and altered hindquarters and the unnatural posture.

Lifecycle of E. rangiferi

Two host lifecycle First Phase: larvae of the nematode

infect the foot of slugs and snails that pass over infected fecal pellets

The snails & slugs are accidentally eaten by the caribou when grazing

Then once in the digestive tract the larvae penetrate the intestinal wall, make way to spinal cord and travel to brain to mature

Lifecycle of E. rangiferi con’t Once young adults, the worms then

travel back down the spinal cord, through the CNS, then the peripheral nervous system to the large flat muscles around the shoulder blades and the hindquarters

This traveling through the CNS and the PNS causes nerve damage resulting in the typical symptoms mentioned

Lifecycle of E. rangiferi con’t To finish the lifecycle, female lay eggs

which enter the blood stream and travel to the lungs

In the lungs the eggs hatch, the larvae crawl up the windpipe and are swallowed

Once in the digestive tract the larvae are expelled in the fecal pellets, starting the cycle over again

Figure 4: Lifecycle of E. rangiferi

Conclusion

Currently, E. rangiferi poses no known threat to other species in Newfoundland, however, sister species have been found in other cervids including moose and deer

North American E. rangiferi is only found in Newfoundland

In countries, such as Norway, the nematode has evolved to also infect other semi-domesticated animals including sheep and goats

Sources

Ball, M.C., Lankester, M.W., and Mahoney, S.P. 2001. Factors affecting the distribution and transmission of Elaphostrongylus rangiferi (Protostrongylidae) in caribou (Rangifer tarandus caribou) of Newfoundland, Canada. Canadian Journal of Zoology 79:1265-1277

Daoust, P.Y. 1989. Elaphostrongylus cervi pathogenic leasions and effects. Presented at Newfoundland Wildlife Disease Conference 1989.

Fong, D. 1989. Elaphostrongylus cervi findings in Newfoundland. Presented at Newfoundland Wildlife Disease Conference 1989.

Handeland, K., Gibbons, L., and Skorping, A. 2000. Aspects of the life cycle and pathogenesis of Elaphostrongylus cervi in Red Deer (Cervus elaphus). Journal of Parasitology 86: 1061-106

Polluck, B., Penashue, B., McBurney, S., Vanleeuwen, J., Daoust, P.Y., Burgess, N.M., and Tasker, A.R. 2009. Liver parasites and body condition in relation to environmental contaminants in Caribou (Rangifer tarandus) from Labrador, Canada. Arctic 62: 1-12

Whitney, H. 1999a. Newfoundland Agriculture: Wildlife disease factsheet. Parasites of caribou (2): fly larvae infestations. Publication AP010 April 21 1999.

Whitney, H. 1999b. Newfoundland Agriculture: Wildlife disease factsheet. Parasites of caribou (3): tapeworm cysts. Publication AP009 April 22 1999.

Whitney, H. 2004. Newfoundland Agriculture: Wildlife disease factsheet. Parasites of caribou (1): brainworm. Publication AP006 July 27 2004.