What are the clinical signs of WNV infection?
Birds that are infected with WNV may show signs such as the inability to fly, incoordination, and abnormal movements. Most crows are simply found dead. Clinical signs of horses which do become ill range from very mild signs to fatal illness. Typical signs include ataxia (incoordination, stumbling, limb weakness) that either appears suddenly or appears gradually and worsens, somnolence (sleepiness), dullness, listlessness, facial paralysis (droopy eyelids, lower lip), and inability to rise. Some horses may develop mild fevers, blindness, muscle trembling, seizures, and many other signs. Rabies, Eastern Equine Encephalitis (EEE), Western Equine Encephalitis (WEE), Equine Protozoal Encephalitis (EPM), and other neurologic diseases should be considered in a differential diagnosis for suspect horses.
