Factsheets

Horses


Overview
Horses are part of an ever growing industry, with over 600,000 horses in the UK, 1.4 million riders and 5 million people with an active interest in the equine industry*. Most people acquire a horse out of choice, so if you make this decision you should think carefully before going ahead. A horse needs lots of love and care, including regular worming, vaccinations and dental care. Owning a horse is time consuming and can be costly; not only will you will need to consider where you will keep your horse, you must also consider the ongoing costs of owning a horse which include accommodation, bedding, feed and healthcare.

In the unlikely event that your horse goes missing it is going to be very difficult for anyone to know who it belongs to, unless your horse carries some form of permanent identification. It is wise to get your horse microchipped or freezemarked, this will avoid heartache in the long run, should your horse go missing or is stolen.

Horses are herd animals, and thrive on being together with other horses. Don’t forget that your horse will need somewhere to graze, a stable for warmth in the winter time, a constant supply of water, feeding daily and regular exercise. It can cost hundreds of pounds a month to care for a horse, including accommodation, food, veterinary care and insurance; there will be other costs, including buying tack and rugs and extra livery charges when you go on holiday.

Horses can live into their thirties, over this time your horse will need lots of care and attention. Being able to provide all of this will ensure you and your horse make the most of your time together.

* Research conducted in 2004 by the Henley Centre for DEFRA and the British Horse Industry Confederation.

Strangles - 'Streptococcus equi infection'

Strangles in a highly contagious infectious disease and can be serious or occasionally even fatal as a result of late diagnosis. Know what to look out for and you will almost certainly avoid the unnecessary suffering of your horse and others.

What is strangles?

Strangles is a highly contagious infectious disease caused by bacteria called Streptococcus equi subspecies equi (S. equi). It is the most commonly diagnosed equine infectious disease in the United Kingdom. It is an infection of the upper respiratory tract (nose and throat) and can cause abscesses in the head region.

Strangles is not usually fatal but can cause severe disease such as not being able to eat or, rarely, struggling to breath due to the abscesses pushing on the airway. Rarely, complications can occur such as bastard (metastatic) strangles, where abscesses can form elsewhere in the body, and purpura haemorrhagica, where the body's immune system starts attacking the body tissues.

How is the disease spread?

The disease is spread either directly from horse to horse or indirectly via fomites. Direct infection occurs by bacteria being shed in the discharge from the nose or abscess of an infected horse coming into contact with a non-infected horse. Also, importantly disease can come from the nose of horses showing no signs of disease (shedders or carriers). Indirect infection occurs when the bacteria being shed from the horse's nose or discharge from an abscess is carried to other horses by any object, such as people's hands/clothing, tack, grooming and yard equipment (fomites). The incubation period is up to 14 days, so there can be up to 21 days between cases showing signs of infection as the abscesses can take up to a week to appear. All horses are susceptible but young horses and sick horses are more likely to show more severe signs.

Horses recovering from Strangles can shed the bacteria for up to 6 weeks after recovering from the illness and still pose a threat to other horses. About 10% of horses recovering from the disease will carry the bacteria within their head (in the guttural pouches) and will be healthy horses, but intermittently be a source of bacteria for months to years that can infect other horses. Identifying these carrier horses is key to stopping the outbreak re-occurring on your yard and preventing spread from yard to yard.

How do I know if my horse has strangles?

Classical strangles

  • Fever (above 38.5°C) accompanied with depression and loss of appetite.
  • Profuse yellow nasal discharge from both nostrils (thick mucus).
  • Swellings on the side of the head and throat which may burst and discharge pus. These abscesses are usually hot and painful and occur some days after the initial fever.
  • Sore throat difficulty eating, extending the head.

Atypical strangles

  • Becoming more common, especially in healthy adult horses.
  • Mild short-term fever may lose their appetite for a brief period of time.
  • Mild clear nasal discharge.
  • No abscess formation.
  • These horses are a risk to other horses and should be treated as infectious.
  • NB: These clinical signs can be seen with a wide variety of diseases and not just strangles.

Isolating affected horses and seeking immediate veterinary attention is essential to stop the spread of the disease.

How will my vet diagnose the disease?

Diagnosis of an individual horse is based on identifying the bacteria cultured (grown) in a lab from throat swabs or aspirates/swabs from abscesses. However, the bacteria is very difficult to grow and will only be found in about 30% of cases. Therefore, a molecular technique (PCR) can be performed on the samples to increase the sensitivity of the test. However, horses that do have strangles may have negative results for culture and PCR; these horses will need another sample at your vets discretion. If the horse has classical clinical signs or the bacteria has been already identified on the yard laboratory confirmation may not be required at the attending vet's discretion.

A new blood test (serology) is available that detects antibodies to the bacteria. The antibodies take up to two weeks to form and therefore the test cannot be used in the initial stages of infection. The antibodies stay elevated for up to six months after infection and therefore a positive test may not mean your horse has strangles at that moment, just that the horse has been exposed to the disease in the last six months. Culture and PCR on swabs would be required to confirm active infection. The blood test can be used to highlight potential carriers. To confirm a horse is a carrier, endoscopy of the head (guttural pouches) is required, and washes need to be taken and submitted for culture and PCR.

Will my horse need to be isolated?

Strict hygiene and disinfection protocols are essential. Personnel and equipment that only look after the isolated horses is ideal. Creating an isolation area which has a foot dip and specific overalls is important. Nothing that enters the isolation area should leave the isolation area without thorough disinfection.

Can my horse be treated?

If the diagnosis is positive either based on clinical signs, culture, PCR or blood test then your vet will discuss treatment options with you.

  • Most cases just need intensive nursing care including rest and a dry warm environment.
  • Feeding soft palatable feeds is important.
  • Abscesses can be hot-packed to encourage them to burst - occasionally your vet may lance the abscess to enable them to drain.
  • Use of antibiotics in strangles cases remains controversial and should be judged on an individual patient basis by the attending vet. However, most horses do not need antibiotics. Severe cases may require antibiotics and using antibiotics in early cases, eg those who have very recently spiked a fever, may be beneficial at your vets discretion.

How can the disease be controlled/prevented?

Recovered horses can shed bacteria for up to 6 weeks, therefore maintaining isolation during this time is critical.

At the end of this time screening the recovered horses for carrier horses is important (up to 10% of affected horses may be carriers). This can be done a number of ways depending on the individual yard circumstances:

  • Culture and PCR of three throat swabs (nasopharyngeal) 5-7 days apart - any horses returning positive results need guttural pouch lavage via endoscopy.
  • Culture and PCR of one guttural pouch lavage via endoscopy.
  • Serology blood test - any horses with positive results need guttural pouch lavage via endoscopy.

Preventing strangles entering a yard

Isolate all horses for three weeks and monitor horses closely for a fever and nasal discharge. Consider performing serology blood test on all new horses moving on to a yard. Horses with positive results should have one guttural pouch lavage via endoscopy and the fluid collected submitted for culture and PCR.

Can my horse be vaccinated against strangles?

In the UK, a live attenuated vaccine (Equilis Strep E - MSD Animal Health), administered by submucosal injection, is available.

In the USA various strangles vaccines are available.

  • Intranasal vaccination:
    • Primary vaccination followed by second vaccination 2-3 weeks later.
    • Annual re-vaccinations recommended.
  • Intramuscular vaccination:
    • Primary vaccinations: 3 doses at 3 week intervals.
    • Annual re-vaccinations.

Ask your veterinarian for further information.