Free-Ranging Bull Elk

Kristen BaumannChristie KranzLuiza Assis

Background

Related to deer, but much larger Also called “wapiti” which means

light-colored deer Common parasites of elk include:

Lungworm (Dictyocaulus) Arterial worm (Elaeophora schneideri) Liver fluke (Fascioloides magna)

Case 1

Yearling bull elk In December, left group, became

solitary Began to frequent nearby barn Clinical signs:

Loss of fear of humans Ataxia Loss of balance Drooping head

Case 1

• Elk was tranquilized, blood drawn• Plasma sample tested for presence of

antibodies against parasitic worms in an ELISA

• Results indicated bull elk was exposed• Suspected P. tenuis• No larvae detected in feces, did find

lung-worm Dictyocaulus• Euthanized in June due to deteriorating

condition

Postmortem Examination

Meningoencephalomyelitis Parasite observed in brain sections Areas of hemorrhages observed in

white matter of spinal cord and brain In lungs, adult female worm with

eggs recovered, Dictyocaulus sp. Severe pulmonary congestion and

infiltration of inflammatory cells

Diagnosis

Central nervous system and pulmonary lesions attributable to two different, simultaneous infections

Dictyocaulus & P. tenuis Dictyocaulus worm found, antibodies

detected in blood Pulmonary lesions

Diagnosis Part 2

P. tenuis Field infected elk rarely pass many

P. tenuis larvae Neurologic disease-L3 migrate

aimlessly through CNS in incidental hosts

CNS Lesions found

Exam Question

Why do elk rarely pass P. tenuis larvae in their feces?