PARASITES OF NEWFOUNDLAND CARIBOU, RANGIFER TARANDUS CARIBOU: AN INTRODUCTION TO ELAPHOSTRONGYLUS RANGIFERI AND ITS EFFECTS Mammalogy 4630 March 7 th , 2011 Kendra Dawe
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.