The herpes epidemic at the Valencia horse show this year has many horse owners worried. But what is Equinene equine herpes (EHV) all about?? And what causes. Consequences?
We explain everything here: The 10 most important points about equine herpes (EHV) and rhinopneumonitis.
#1 – Which viruses are responsible for the EHV?
Responsible for this disease are the Equine herpesviruses: EHV-1 and EHV-4. There are a total of 5 forms of this virus, but only the EHV-1 and EHV-4 forms cause rhinopneumonitis in horses.
#2 – Is it true that there are several forms of rhinopneumonitis in horses?
Yes, it is true ✅. Rhinopneumonitis can occur in 3 forms: respiratory disease, nerve area and virus abortion of mares.
The virus EHV-1 can be the 3 forms of rhinopneumonitis Trigger. The virus EHV-4 conditional primarily the respiratory disease. A few cases of EHV-4 have been detected during viral abortion, but this remains a rarity.
#3 – How is the virus transmitted?
EHV-1 is only slightly resistant in the field. However, it can be present for several days in the Straw in the box z. B. superior ..
The virus is transmitted primarily through coughing and nasal discharge from infected horses (regardless of whether these horses are sick or merely asymptomatic carriers of the virus). In the case of the viral abortion form, the infection can also be transmitted through the Remnants of the foal are transmitted. These include: the fetus, vaginal secretions, and contaminated surfaces.
The incubation period of the virus is 2 to 10 days.
It is a latent virus
The virus can be be in the horse's body for a long time without symptoms appearing. This is referred to as latent, d. h. sleeping or inactive. The infection can be triggered abruptly by stress or other treatment … as with human herpes, by the way! You surely know the herpes on the mouth that comes back from time to time when you are stressed? This is also such a latent herpesvirus!
It is estimated that 60 to 70% of horses are latent virus carriers (IFCE). This means that they carry the virus but are neither symptomatic nor sick. If you have already had a case of rhinopneumonitis in your stable, you can be almost sure that your horse is a carrier of the virus.
#4 – What are the symptoms of rhinopneumonitis??
Symptoms resemble an attenuated flu. Horses have fever, nasal discharge, dry cough and possibly eye discharge. This disease condition lasts for 1 to 2 weeks. The outcome is very rarely fatal. However, since the horse's immune system is weakened, it can quickly become a bacterial infection added. This complicates things even more.
Symptoms vary greatly from one horse to another: Ataxias, disturbances in the coordination of movements , which go up to paralysis, fever, incontinence ..
Some horses recover completely. others die by euthanasia or of natural causes. This form remains very rare, but unfortunately is the predominant one in the case of the Valencia tournament.
Precision in advance: An abortion in the mare corresponds to the "miscarriage" in the female.
The abortion of the foal occurs late (between the 9. and 11. month of gestation). The mare shows no warning signal or symptom on, which makes it difficult to assess the situation.
mares are primarily contaminated with the respiratory disease. Since the virus remains undetected for a long time, it can lead to abortion even years later. 😕
#5 – How to diagnose rhinopneumonitis?
There are several methods. As with the Covid PCR method (Polymerase Chain Reaction) as a widespread! This is to check whether the virus DNA accumulates in the horse's body is located. It is sufficient to send a nasal sample and a blood sample to the laboratory. This method is the best when there is an emergency. It must be performed by a veterinarian.
With the nerve form of the disease can be a Analysis of the Brain spinal cord(s)-Fluid bring the answer. In the case of viral abortion, an analysis of the shedding can be carried out.
#6 – What are the treatments for rhinopneumonia??
There is no direct cure. This means that the cause of the disease cannot be treated, but only the consequences. So you can give the horse z. B. Prescribe cough relievers. Only the symptoms can be relieved in the respiratory and nervous forms of the disease.
In the case of viral abortion, no treatment is necessary because the mare generally shows no symptoms.
#7 – What about vaccination against rhinopneumonitis??
There is a vaccination against EHV-1 (all 3 forms) and EHV-4 (respiratory disease).
"All vaccines approved in France contain the valence EHV-1, some contain only this (Pneumequine®) and one contains 2 values EHV-1 and EHV-4 (EQUIP EHV 1.4® ): Its protection against the respiratory form is improved (horses in training z. B.), but the protection against the virus abortion is identical." (IFCE)
Vaccination is compulsory only for breeders (stallions) and some broodmares (Trotteur Francais, Thoroughbred, AQPS). For all others, vaccination is advised.
Any single vaccine alone does not provide 100% protection against the 3 forms. The risk is only minimized. There are fewer diseases and abortions among vaccinated horses and consequently fewer transmissions. Its effectiveness is very high with 75% less abortions in vaccinated mares.
According to IFCE: 80% of broodmares are infected at the age of less than 10 months.
Effectiveness of vaccination alone increases if horses from the same barn are vaccinated. This is called a herd vaccination. The problem here is that the vaccination rate is very low and so epidemics occur repeatedly.
"The vaccination protocol is the same as the group with 2 injections 4 to 6 weeks apart for the initial vaccination, followed by an annual booster. A booster vaccination every 6 months is indicated to stimulate the immune system. For pregnant mares, a vaccination imm 5., 7. and 9. Month." (RESPE)
#8 – Can rhinopneumonitis in horses be transmitted to humans?
No. ❌ The virus is peculiar to the horse breed: Humans cannot become infected with this disease infect. However, you can have the virus on your hands or clothes if they have not been washed properly. This can lead to transmission to another horse. So remember to disinfect the material and wash your cell phone if there is a horse with rhinopneumonitis in your stable.
#9 – How to narrow down the epidemic?
Viral containment measures are not particularly pleasant, but are necessary to link further transmission.
The most efficient measure is quarantine, d. h. the diseased horses should remain in place and not be transported. Horses new to the barn during this period should be isolated for 3 weeks. Taking the temperature daily is advised.
The following hygiene measures should be taken:
– Isolation and monitoring of sick horses – Use of protective clothing (blouse, overshoes, gloves) when in contact with sick horses – Care and feeding of healthy horses, Disinfection of hands and shoes (if no protection) between contact with horses – Use of different material for healthy and infected horses – Regular disinfection of stalls and destruction of bedding – Keeping healthy horses away from infected horses for 3-4 weeks – Prohibition to carry manure to pastures – Separation of young horses and broodmares of sport horses, as they are often virus carriers.
It is important that infected horses remain isolated and the barn quarantined until full recovery (disappearance of all symptoms) is achieved.
#10 – Should transports to the tournament be avoided?
I would like to quote here, the crisis statement of the RESPE (French network for epidemic surveillance of equine diseases) during the 2018 crisis in France. Many tournaments have been cancelled in view of the health situation on the ground. The mediatization of the disease this weekend already canceled. Some tournaments are held in compliance with preventive measures.
Within the coming weeks, many events are planned with a large number of horses. Some of these horses were in high-risk areas in the weeks leading up to the event.
The Crisis Committee advises all participants or organizers of tournaments in their localities against hosting or. Participants of this from, the location should be in suspicion and/or. have received confirmation of having harbored infected horses.
The committee also calls on all horse owners who have participated in a tournament in the risk area to keep a particularly close eye on their horses and, in case of suspicion, not to enter tournament grounds until the analysis results are available." crisis management 27/04/2018
I hope this article has helped you better understand rhinopneumonitis, EHV-1 and EHV-4, and what to do about them.
See you soon Camille Saute
R&D Manager at Equisense
Daix et S. Pronost, " Herpès Virus Equin 1 ", RESPE, 2014. [En ligne]. Disponible sur: RESPE. [Consulte le: 30-avr-2018]. AVEF, C. Laugier, I. Barrier, C. Pitel, B. Ferry, et P. Tritz, " La rhinopneumonia ", Equipaedia, 2016. [En ligne]. Disponible sur: Equipaedia [Consulte le: 30-avr-2018].