VACCINATIONS

Why do we vaccinate horses?

Vaccinations are given to train the immune system to recognise and fight specific diseases which are common in the horse world. The idea is to protect horse health, prevent serious disease, stop the spread of infections and reduce the economic effect of disease outbreak.

In recent years, there has been a notable increase in infectious diseases, equine herpes virus (EHV) especially. As such, appropriate vaccination of horses is of utmost importance to reduce the disease prevalence where possible.

What can we vaccinate horses for?

Most common vaccines given to horses are for:

  • Tetanus
  • Equine Influenza

Other diseases which we can vaccinate for, depending on risk and breeding status, are:

  • Equine Herpes Virus (EHV)
  • Streptococcus equi subsp. equi (Strangles)
  • Rotavirus – mares in foal
  • Equine Viral Arteritis (EVA) – breeding stallions

 

Equine Herpes Virus (EHV)

Recently there has been a significant rise in the number of cases of EHV in the UK. EHV in horses can present in a variety of ways:

  • Respiratory – most common form. This usually affects horses for 1-2 weeks and provided there are no complications, horses tend to make a good recovery. EHV may also be a cause of a drop in performance or energy without any other clinical signs.
  • Neurological – rare but severe. Symptoms include weakness, inability to urinate and poor co-ordination of limbs. This form of the disease can be fatal.
  • Abortion – rare but very serious. Mares suddenly abort their foal. Aborted material is highly contagious.

Vaccination protocol

To provide protection against respiratory disease and reduce viral shedding, which helps to lower the risk of neurological disease, horses are given a primary course of 2 vaccinations 4-6 weeks apart. The horse must then have a booster vaccine every 6 months thereafter.

In competition horses administration of a booster vaccination before the start of the season could help reduce the risks of a horse developing a sudden loss in performance or energy due to a mild EHV infection.

To help prevent abortion in mares in foal; vaccinations are given at 5, 7 and 9 months of pregnancy.

 

Equine Influenza

Equine influenza is a highly contagious, respiratory disease in horses. The disease itself is not usually fatal but due to its rapid spread and performance limiting nature, vaccination is required to comply with most equine competition body rules.

Clinical signs of equine influenza:

  • Fever (>38.3°C)
  • Dry, harsh cough
  • Nasal discharge
  • Depression or weakness
  • Loss of appetite

Vaccination protocol

Usually in combination with tetanus vaccine.

First vaccination (V1)

Day 0

Second vaccination (V2)

Day 21-60

Third vaccination (V3)

Day 120-180 after V2

Boosters

6 monthly

This protocol is set out by the FEI and BHA. Most horses require annual boosters only after their primary course however, if you take your horse out to events, always check booster requirements with the regulatory body.

Horses must not compete within 7 days of a vaccination being given.

Unfortunately, if your horse is competing under a specific regulatory body (such as pony club or riding club) and a booster vaccine is missed, the primary course must be re-started to comply with competition rules.

Tetanus

Tetanus is caused by a bacteria called Clostridium tetani which is found in soil, dirt and manure. Clinical disease is thankfully rare and usually occurs after the horse sustains an injury that breaks the skin, these injuries do not always have to be obvious! Vaccinating for tetanus is considered an essential part of good horse health management because once a horse develops clinical signs of tetanus, the disease is difficult to manage and 80% of affected horses will die.

Clinical signs of tetanus:

  • Localised stiffness progressing to whole body stiffness
  • Muscles spasms
  • Sensitivity and severe pain on palpation
  • Erect ears, stiffness of the tail, dilated nostrils and protruding third eyelid

Vaccination protocol

Usually in combination with influenza vaccination.

Primary course consists of 2 vaccines given 4-6 weeks apart. A booster is then given 12 months after the second vaccine and thereafter, boosted every 2 years.

What if my horse has a wound but is not vaccinated?

Recommendation is that the horse is given tetanus antitoxin to protect the horse in the immediate future, we can also start a vaccination course at the same time, to cover in the long-term.

Tetanus cover is essential for all colts or stallions being gelded.

Rotavirus and Equine Viral Arteritis (EVA)

Rotavirus primarily affects foals under 6 months of age and can cause severe, watery diarrhoea, electrolyte imbalances and marked dehydration. A vaccination can be given to mares in foal to protect the foal in its’ first year of life.

EVA is a notifiable disease in the UK due to its contagious nature and potentially serious consequences on breeding stock. Vaccinations can be given to breeding stallions, but a strict protocol must be followed.

Please contact the office to discuss requirements for the above vaccinations if you think your horse needs them.

Strangles

Strangles is a highly contagious bacterial infection of the upper respiratory tract of horses, donkeys and mules. The prognosis in uncomplicated cases is good however, recovery times can be prolonged. It is strongly recommended that yards restrict all movement on and off the premises and strict biosecurity measures are implemented until the outbreak has been resolved.

Clinical signs of strangles:

  • Fever (often > 39°C)
  • Depression, inappetence and lethargy
  • Nasal discharge
  • Coughing and/or difficulty swallowing
  • Swollen/abscessated lymph nodes of the head

Vaccination protocol

The primary course consists of 2 vaccines given 4 weeks apart, with booster vaccines then given 6 monthly.

The purpose of this vaccine is to reduce severity of clinical signs and the number of abscesses that form during the acute stages of the disease. Vaccination does not prevent infection and should not replace biosecurity measures.

The vaccine is formulated such that any diagnostic testing required in the future, such as a pre-movement blood test, will not be affected.

Vaccination reactions

Thankfully vaccine reactions are rare, however, we do see them from time to time. It is important to be aware of what to look out for and how they can be managed. Some horses are particularly prone to reactions and are managed on an individual basis.

Signs of a vaccine reaction include:

  • Soreness at the injection site
  • Swelling of the injection site
  • Fever (>38.3°C)
  • Loss of appetite/general depression or lethargy

It is important to note that the strangles vaccine caries a higher risk of reaction (approximately 1 in 10 horses).

If you suspect your horse has had a reaction, telephone the office on 01342 823011 to report it and a vet will be in contact to discuss any necessary treatment.

Priors Farm Equine Veterinary Surgery

Priory Road,

Forest Row,

East Sussex.

RH18 5JD

Office telephone: 01342 823011

Office email: reception@priorsfarm.co.uk