- EVE is an infectious mosquito-borne disease of horses characterised clinically by paralysis and other signs of nervous derangement caused by several virus types.
- The viruses can cause serious human disease as well as infecting poultry and sometimes mammals.
- The virus responsible can cause Venezuelan Equine Encephalomyelitis (VEE), Western Equine Encephalomyelitis (WEE) and Eastern Equine Encephalomyelitis (EEE).
- Clinical Signs
- The severity of clinical signs varies according to the virus involved but there are some common themes. The incubation of the disease after infection with the virus is from 1 to 3 weeks. In the initial stage there is fever, which may be accompanied by depression and loss of appetite, but the reaction may be so mild it goes unnoticed.
- The nervous signs are hypersensitivity to sound and touch with periods of excitement and restlessness, with apparent blindness. Affected horses may walk blindly into objects or walls. Muscle twitchings may occur in the face and shoulders. A period of severe depression follows. Affected horses stand with their heads hung low and may have a half-chewed mouthful of feed hanging from their lips. The animal may appear to be asleep and is unable to hold up his head, often resting it on some solid object.
- Protection
- There are no vaccines currently approved for use in the EU to protect against the Encephalomyelitis viruses mentioned above.
- Risk of infection can be reduced by protection from the vectors.