Equine Viral Encephalitis
Introduction:-
This disease is not present in Pakistan.
It has three types:
Epidemiology:-
The virus belongs to α-viruses of the family Togaviridae. They need
arthropod vectors for their transfer. All vectors are susceptible to Equine
viral encephalitis. It disappears within hours in infected tissue. This disease
is more prevalent in the USA and the arthropod vector is mosquitoes. Mammals like a horse are accidental hosts. It is zoonotic in nature and causes mild type
infection or clinical encephalitis in human beings. In human’s infection occurs two weeks after visiting an infected horse.
Mild types:-
- Mild Influenza
- Anorexia
Clinical encephalomyelitis
Clinical encephalomyelitis is seen in those having an immunocompromised system such as young ones and old animals.
Mild influenza pathogenesis:-
At first there
is transitory viremia. Then the virus reaches the brain and affects the grey
matter which may lead to blindness. The white matter is myelinated. The spinal
cord is affected leading to paralysis.
Clinical findings:-
The incubation
period in different types is as follows.
In Venezuelan → 1-6 days
The following clinical signs may be found in animals with Equine viral encephalitis.
- High rise
of temperature which persists for 24-48 hours
- Hypersensitive
to touch
- Involuntary
muscle contraction
- Erection
of the penis in male horses
- Effected
horse severally depressed with head down
- Absence of
proper chewing. Half chewed food structure in the mouth
- Paralysis
and animal go to recombinant position
- Incoordination
in movement
- Caseation of urine and defecation
- Complete Paralysis at the end
Treatment:-
- No specific treatment.
- Culling of animal suggested.
