Below is a summary on EHV 1. THERE IS NO VACCINE FOR IT!
Currently there are eight known herpes viruses that infect horses. Of the eight, two are of economic importance. EHV-4 causes respiratory disease in young horses and neurological disease infrequently. EHV-1 is associated with abortion, respiratory disease, and the neurologic form of the disease in horses. A herpesvirus strain associated with myeloencephalopathy has not been clearly demonstrated but genetic analysis has shown similarities among isolates from outbreaks of the neurlogical form (EHM). Most horses contract these two infections in their first year of life without serious disease occuring. After recovery horses continue to carry the herpes virus in a dormant state. This article discusses transimission, clinical signs, treatment, and prevention of
Transmission
EHV has a worldwide distribution. The neurological form is more comon in the winter and spring months. Pregnant and lactating mares seem more susceptible. Persistant latent infections can cause outbreaks in closed herds. The virus can be contracted through ingestion or breathing in aerosolized respiratory secretions or aborted material. Experimentally, clinical signs begin about 7 days following exposure.
Cause
Primary infection of the nervous system is not the cause of the neurological disease. The virus has a predilection for the endothelial cells of the cappilaries of the nervous system. An immune mediated vasculitis results in ischemia causing the lesions in the nervous system. Prior exposure may be necssary for clinical signs to develop.
Clinical Signs Disease may effect a single animal or more often, multiple horses in a herd. There may be a recent history of contact with an abortion or horses with respiratory disease or there may be a recent addition to the herd. Commonly fever, lethargy, respiratory disease, and inappetence of 1 to 7 days duration occur before an acute onset of neurologic signs. Some horses that develop EHM may have had relatively little in the way of other signs of disease. Not all horses that become sick during an outbreak of EHV-1 develop EHM.
Most horses will have an acute onset of symmetrical weakness and incoordination with the hind limbs worse than the front. However the neurologic signs can be asymetrical or the front affected worse than the rear. Generally the severity of the condition will stabilize 24 to 48 hours after the onset of signs and then slowly improve during the following weeks to months. Severity may range from mild incoordintion to severe incoordination, recumbency, or rarely peracute death. Also sometimes seen is
cough,
abortion,
diarrhea,
ventral or limb edema,
colic, small hemmorages on the nasal mucosa
eye lesions, ocular lesions include:
redness
hypopyon
retinitis
retinal hemmorage and (rarely) detachment
cranial nerve deficits (17% of the time)
urine retention and dribbling,
anal sphincter paresis, and fecal retention may also occur.
"I tend to listen most to the advice of the person least likely to give it."
Currently there are eight known herpes viruses that infect horses. Of the eight, two are of economic importance. EHV-4 causes respiratory disease in young horses and neurological disease infrequently. EHV-1 is associated with abortion, respiratory disease, and the neurologic form of the disease in horses. A herpesvirus strain associated with myeloencephalopathy has not been clearly demonstrated but genetic analysis has shown similarities among isolates from outbreaks of the neurlogical form (EHM). Most horses contract these two infections in their first year of life without serious disease occuring. After recovery horses continue to carry the herpes virus in a dormant state. This article discusses transimission, clinical signs, treatment, and prevention of
Transmission
EHV has a worldwide distribution. The neurological form is more comon in the winter and spring months. Pregnant and lactating mares seem more susceptible. Persistant latent infections can cause outbreaks in closed herds. The virus can be contracted through ingestion or breathing in aerosolized respiratory secretions or aborted material. Experimentally, clinical signs begin about 7 days following exposure.
Cause
Primary infection of the nervous system is not the cause of the neurological disease. The virus has a predilection for the endothelial cells of the cappilaries of the nervous system. An immune mediated vasculitis results in ischemia causing the lesions in the nervous system. Prior exposure may be necssary for clinical signs to develop.
Clinical Signs Disease may effect a single animal or more often, multiple horses in a herd. There may be a recent history of contact with an abortion or horses with respiratory disease or there may be a recent addition to the herd. Commonly fever, lethargy, respiratory disease, and inappetence of 1 to 7 days duration occur before an acute onset of neurologic signs. Some horses that develop EHM may have had relatively little in the way of other signs of disease. Not all horses that become sick during an outbreak of EHV-1 develop EHM.
Most horses will have an acute onset of symmetrical weakness and incoordination with the hind limbs worse than the front. However the neurologic signs can be asymetrical or the front affected worse than the rear. Generally the severity of the condition will stabilize 24 to 48 hours after the onset of signs and then slowly improve during the following weeks to months. Severity may range from mild incoordintion to severe incoordination, recumbency, or rarely peracute death. Also sometimes seen is
cough,
abortion,
diarrhea,
ventral or limb edema,
colic, small hemmorages on the nasal mucosa
eye lesions, ocular lesions include:
redness
hypopyon
retinitis
retinal hemmorage and (rarely) detachment
cranial nerve deficits (17% of the time)
urine retention and dribbling,
anal sphincter paresis, and fecal retention may also occur.
"I tend to listen most to the advice of the person least likely to give it."
)
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also pleasant hollow Farm(PA) last year, maybe the vaccine developers need to have a closer look athis virus,if it is one,
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