Control and Treatment of Venereal Diseases

Control and treatment of venereal diseases:

CEM – EVA – EIA – EHV1

 

Contagious Equine Metritis (CEM)

Contagious Equine Metritis is a bacterial venereal disease caused by Taylorella equigenitalis.

  • Transmission:

The disease is transmitted during mating (including artificial insemination)

  • Clinical signs:

Infected stallions do not show clinical signs and are persistent carriers of the bacteria on external genitalia. The disease causes infertility and abortion in mares; some mares recover spontaneously, whereas a smaller percentage become chronic carriers, with the bacteria localising in the clitoral sinuses and fossa

  • Diagnosis:

Diagnosis is confirmed by culture or PCR from a swab taken from:

  • The clitoral sinuses and fossa (mares)
  • Prepuce and surface of the penis, fossa glandis and urethral sinus (stallions)
  • Prevention: The disease can be prevented by strict adherence to the recommendations for swabbing in the HBLB Code of Practice. The swabs should be taken from mares and stallions after 1st January of the year in which breeding activity is planned

 

Equine Viral Arteritis (EVA)

Equine Viral Arteritis is an infectious disease caused by equine arteritis virus (EAV).

  • Transmission:

The disease is transmitted during mating (including artificial insemination), but also via aerosol spreading from the respiratory system

  • Clinical signs:

The vast majority of EAV infections are inapparent or subclinical, but occasionally outbreaks are characterized by any combination of influenza-like illness in adult horses (e.g. fever, depression, nasal discharge, conjunctivitis), abortion in pregnant mares, and interstitial pneumonia in very young foals.

  • Diagnosis:

Diagnosis is confirmed by serology (blood sample for detection of the antibodies against the virus) or virus isolation from nasopharyngeal or conjunctival swabs, urine, semen or aborted material.

  • Prevention: The disease can be prevented by strict adherence to the recommendations for sampling in the HBLB Code of Practice. The blood sample should be taken from mares and stallions after 1st January of the year in which breeding activity is planned

 

Equine Infectious Anaemia (EIA)

Equine Viral Arteritis is an infectious disease caused by equine infectious anaemia virus (EIAV).

  • Transmission:

The disease is most often transmitted by insect vectors (e.g. horseflies). Other possible infection routes are venereal and transplacental transmission

  • Clinical signs:

The disease is characterised by recurrent episodes of fever, lethargy, inappetence, anaemia

  • Diagnosis:

Diagnosis is confirmed by serology (blood sample for detection of the antibodies against the virus)

  • Prevention: The disease can be prevented by strict adherence to the recommendations for sampling in the HBLB Code of Practice. The blood sample should be taken from mares and stallions after 1st January of the year in which breeding activity is planned

 

Equine Herpesviruses (EHV)

EHV is a common virus that affects horse populations worldwide. Two forms of the disease exist; EHV-1, which causes respiratory disease, abortions and paralysis; and EHV-4, which usually causes respiratory disease only but can cause abortions

  • Transmission:
  • Aerosol droplets from the respiratory tract e.g. coughing and snorting
  • Contact with aborted foetus, foetal fluids and membranes
  • Foals born from infected mares are highly contagious and shed the virus in the environment
  • Indirect transmission from the environment as the virus can survive for several weeks
  • Horses commonly act as carriers and shed the infection without showing any clinical signs
  • Clinical signs:
  • Clinical signs develop 2 weeks to months after infection and include mild fever, coughing and nasal discharge. Foals that are infected in the uterus from the mare are usually born with weakness, jaundice, difficulty breathing and neurological signs. They usually die within 3 weeks. EHV-1 is also responsible of abortions and paralysis
  • Diagnosis:

Diagnosis is confirmed by virus isolation from nasopharyngeal swabs, blood samples or aborted foetuses and placenta

  • Prevention: Vaccination against Rhinopneumonitis caused by Equine Herpesvirus Type 1 (EHV-1) is particularly important for the pregnant mare since infection can result in abortion. EHV-1 is highly contagious, with transmission usually occurring through the respiratory route. Exposure to horses shedding the virus, or reactivation of the latent virus with the stress of pregnancy can result in infection; the virus can cross the placenta and cause the foal to be aborted. Abortion can occur from 2 weeks to several months after infection. Abortion usually occurs in late pregnancy but can occur as early as the 4th month of pregnancy. If a mare is infected during late pregnancy, her foal may be stillborn or born alive, but die within a few days of birth. It is recommended that mares be vaccinated against EHV-1 in the 5th, 7th and 9th month of her pregnancy. In higher risk situations where your mare will have exposure to non-vaccinated horses or horses that travel, it is recommended that the first EHV-1,4 immunisation be given at 3 months.

 

 

Due to the severity of EHV infection which can cause abortion, and our intent to offer the most secure environment to the pregnant mares housed at the practice, owners of ALL mares coming to Pool House Equine Clinic for foaling MUST:

Vaccinate the mare against EHV-1 in the 5th, 7th and 9th month of pregnancy or

provide one EHV-1 negative (seroconversion) blood sample (or two EHV-1 negative blood samples taken 14 days apart, in case the first sample results positive)

 

DOCUMENTATION AND RESULTS OF THESE TESTS MUST BE PROVIDED TO US (equineadmin@poolhousevets.co.uk) AT LEAST ONE WEEK BEFORE ARRIVAL AT THE CLINIC

 

·         Special arrangement will be made for emergency admissions

 

 

If you have any questions or if you need advices on how to organise your mare’s vaccination programme or routine pre-breeding tests, please contact us at the clinic on 01283 – 799700

Pool House Vets