EHV is a bad news virus to have on your farm if you are breeding with horses. There are 8 serotypes of EHV but EHV Ⅰ and Ⅳ are the two that cause the most problems.
Being a virus EHV belongs to those frustrating diseases that cannot be treated with any specific medicines e.g. antibiotics. This means that managing the disease and symptomatic treatment is all there is. Prevention and avoidance are the best management tools.
EHV can spread easily and rapidly through a herd. Not all animals will show symptoms, some may recover, some may succumb to secondary infections and some may become carriers.
EHV Ⅳ is a virus that tackles the upper respiratory system and causes a runny nose and fever. This may become a longstanding “cold” type illness with a thick mucoid nasal discharge and may even eventually lead to a pneumonia secondary infection. The incubation period is 2-10 days and the infection can last for weeks especially when secondary infections set in. Recovery and return to full performance can take several months.
EHV Ⅰ can cause respiratory, neurological and REPRODUCTIVE problems. This guy you really don’t want on your farm.
Infected horses can abort from a few weeks to several months after infection. With EHV Ⅰ this is often the first sign of problems. In freshly exposed herds this can lead to “abortion outbreaks”. The abortion is caused by the virus that crosses over from the mare to the foal. Once the foal has died the mare aborts. If foals are infected and lives to be born they may die shortly thereafter due to kidney, lung and liver damage.
The virus is spread predominantly by nasal discharge. The body really struggles to rid itself of the virus and it can relapse in certain animals leading to intermittent repetitive abortions. Future fertility is not infected.
Diagnosis is confirmed by blood tests:
- ELISA tests measure antibody levels in the reaction of the body to exposure to the virus or the vaccine.
Once the virus i.e. has left the body the ELISA test will still test positive.
- PCR tests measure the DNA of the virus e.g. the virus must be present in the sample in sent to the laboratory for the result to be reliable.
Once the virus has left the body the PCR test will be negative.
Testing unvaccinated naive herds is reliable if ELISA is used. Once the herd has been vaccinated PCR tests are more reliable. Unfortunately the virus is not necessarily always present in all samples – this can lead to false negative tests.
Enting moet herhaaldelik geskied tydens dragtigheid om aborsie te voorkom. Perde word weer dragtig maar toekomstige dragtighede moet ook weer beskerm word deur herhaalde enting. Entstof is ongelukkig duur en soos verlede jaar van tyd tot tyd nie beskikbaar nie.
Voorkoming is dus uiters belangrik.
By enkel kuddes moet ’n mens baie versigtig wees met inkomende perde dat hulle nie ’n gesonde kudde aansteek.
Siek gevalle moet onmiddellik geïsoleer word in ’n hospitaalkamp vêr weg en wind af van die ander perde aangesien die virus so maklik aansteek.
Pneumabort van Zoetis:(EHV1)
As mens begin en merries is dragtig: Ent 2ml op 5,7 en 9 maande daarna jaarliks
Jong perde: 2ml en skraagdosis 3-4 weke later en 6 maande later daarna jaarliks
Equivac 4 van Zoetis(EHV1&4)
Aanvanklik: Twee doserings 3-4 weke uitmekaar
Jaarliks: Jaarlikse skraagdossisse word benodig