A moose parasite which usually affects whitetail deer, attacks the brain.
Brain worm (P. tenuis) is a brain parasite that is often carried by whitetail deer with little to no effect.
If a moose is infected by the parasite, it causes them to act like a zombie, a behavior that eventually leads to their death. Find out more about this intriguing condition in this PBS video.
This parasite resides in the membrane of the brain or spinal column. It was believed that the moose parasite itself was responsible for the death, but studies show that it is not. It just makes the moose more susceptible to other forms of mortality.
Symptoms include turning the head to one side, circling, and often falling over due to an inability to stand. It is a shame for any animal to pass in such a horrible manner, but no one said Mother Nature was kind.