Moose Disease

Presented By:

Andrew & Simla

Location

Moose observed at Elk Island National Park

40 km east of Edmonton in central Alberta, Canada

Population estimated at 339

Bulls (adult males),Cows (adult females),& Calves (male/female <1 yr old)

Study

Moose were observed from a vehicle using binoculars

Grooming behavior was observed Oral grooming (tongue, teeth, or both) Scratch grooming (hoof of hind leg) Head-rub grooming (side of head)

Relative hair loss determined Shape of the “bell”

Tuft of hair hanging under the lower jaw

Observations October through April (Winter)

Proportion of hair loss & rate of grooming increased

Highest in March and April

Premature loss of winter coat

Increased grooming: Feeding activity Hair loss

Observations

Hypotheses?

Results

Hair loss and increased grooming due to winter ticks (Dermacentor albipictus)

Winter Ticks Egg

Laid in spring time in ground litter 3-6 weeks they hatch

Larva Bunch together & wait for cold weather (autumn) Climb nearest plant and wait for moose A moose brushes against plant

Tick “quests” (waves its forelegs and attempts to latch onto the moose)

Crawl down hair to base & bury mouth into flesh After feeding they molt into nymphs

Winter Ticks

Nymph Feed and molt into adult male and female

ticks Takes several weeks

Adults Mate Female takes her last feed

Takes several days Engorges to several times her size

Female falls off in early spring and lay eggs

Winter ticks on moose

Moose will aggressively groom themselves to attempt to dislodge the ticks

Results in hair loss Hair loss excessive in late winter when adult

ticks are feeding Body heat loss and blood loss

Spend more time grooming Increased energy expenditure

Less time foraging for food Reduced mass gain and depletion of reserves

Effect on Ungulate Populations

• Three main hosts:

Moose (Alces alces),

Elk (Cervus elaphus),

White-tailed deer (Odocoileus virginianus).

• Decrease in populations due to:

Hair loss and damage (hypothermia),

Chronic weight loss (reduced growth and fat stores),

Anemia.

Numbers on Decreased Populations

• Isle Royale moose population (210 square mile):

Year 2000: 1100

Year 2007: <400

• Alberta, Canada proportion of moose (January 1 to April 30, 1999):

92% had evidence of hair loss

28% of them were dead.

• Alberta, Canada proportion of calves:

January 1998: 0.44

March 1998: 0.26

Ideas about Management or Control?

http://wildlife1.usask.ca/wildlife_health_topics/images/tick_stages.jpg

Ideas about Management or Control

• Prescribed burning for control (Alberta, Canada):

• Reduces numbers of some tick species,

Removes the leaf litter (forested areas),

Does not completely remove duff layer (forested areas).

Success of prescribed burning:

Habitat type being burned,

Weather conditions prior to the burn,

Fuel load in the burn site.

Ideas about Management or Control

• A slow, hot fire must be maintained to remove duff and litter layer:

Between snowmelt and leaf out in spring,

Burning of engorged females (survive and lay eggs), reducing numbers of larvae transmission for fall.

• A fast, hot fire: In fall (September and early October) to reduce numbers of larvae,

Might cause a decrease forage amount available to ungulates!

Ideas about Management or Control

• Using approved acaricides by dipping, spraying the entire animal with high-pressure sprays or whole animal dusts.

• Insecticide-impregnated ear tags offer some protection and control when ticks are infesting mainly the ears.

• Long-term pasture rest and rotation.

• Hire a guinea fowl !

References Drew, Mark; W. M. Samuel; G. M. Lukiwski; J. N. Willman. 1985. “An

Evaluation of Burning for Control of Winter Ticks, Dermacentor albipictus, in Central Alberta.” Journal of Wildlife Diseases. 21(3): 313-315.

Mooring, Michael & Samuel, W. 1999. “Premature loss of winter hair in free-ranging moose (Alces alces) infested with winter ticks (Dermacentor albipictus) is correlated with grooming rate.” Canadian Journal of Zoology. 77: 148-156.

Musante, Anthony; Pekins, Peter; Scarpitti, David. 2007. “Metabolic impacts of winter tick infestations on calf moose.” Alces.

http://www.sciencedaily.com/releases/2007/08/070817210729.htm

http://www.drovers.com/directories.asp?pgID=714&ed_id=2058

http://www.pested.msu.edu/Resources/bulletins/pdf/2601/LPNE2601chap3.pdf

http://wbztv.com/health/guinea.hens.guinea.2.748337.html