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ENCEPHALITIS

Encephalitis is, by definition, inflammation of the brain but in general usage it includes those diseases in which inflammatory lesions occur in the brain, whether there is inflammation of the nervous tissue or primarily of the vessel walls. Clinically, encephalitis is characterized initially by signs of involuntary movements, followed by signs caused by loss of nervous function.

The meninges and spinal cord may be involved in an encephalitis, causing varying degrees of meningoencephalomyelitis.

ETIOLOGY

Many encephalitides of large animals are associated with viruses but other infectious agents are also common. Some causes are as follows.
All species
1- Viral infections - rabies, pseudorabies,
2- Bacterial infections of neonatal farm animals Listeria monocytogenes
3- Toxoplasmosis, which is not a common cause in any species
4- Sarcocystosis.
5- Verminous encephalomyelitis - migration of larvae of parasitic species
that normally have a somatic migration route, e.g. Setaria spp.

CLI NICAL FINDINGS

The clinical findings that can occur in encephalitis are combinations of:
o Subtle to marked changes in behavior
o Depression
o Seizures
o Blindness
o Compulsive walking
o Leaning on walls or fences
o Circling
o Ataxia.
CLINICAL PATHOLOGY

1- Hemogram

In the horse, complete and differential blood counts and serum chemistry profiles
are recommended for most neurological cases.
2-Serology.
3-Cerebrospinal fluid examination

TREATMENT

1- Antimicrobials are indicated for bacterial meningoencephalomyelitis.
2-supportive treatment by intravenous fluid and electrolyte therapy or stomach
tube feeding during the acute phase.
3-Sedation during the excitement stage may prevent the animal from injuring itself,
and nervous system , stimulants during the period of depression may maintain
life through the critical phase.