Merck Manual

Please confirm that you are a health care professional

WNV encephalomyelitis, horse
WNV encephalomyelitis, horse

Horse with WNV encephalomyelitis: tester is able to easily displace the horse to the left on pulling its tail (left); tester is unable to displace the horse at all to the right, demonstrating asymmetrical weakness (right).

Courtesy of Dr. Maureen Long.