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  • News regarding strangles

    Posted on by Abii Dowdy

    There are a couple of confirmed cases of strangles in the area. Appropriate action has been taken and all outbreaks are fully contained.

    Strangles is endemic within the population of our horses so sporadic cases are not uncommon. The important thing is not to panic.

     

    What is strangles?

    Strangles is caused by the bacterium Streptococcus equi. It is a highly contagious infection of the upper respiratory tract causing a variety of clinical signs. Horses can become carriers if the infection persists long term

     

    Clinical signs to look out for?

    • Fever (temperature > 38.5°C / 101.3°F)
    • Dull/depressed
    • Reduced appetite, signs of a sore throat (struggling to eat/difficulty extending the neck)
    • Swellings under the jaw, behind the jaw or below the ears
    • Thick discoloured nasal discharge
    • Abscesses under the jaw, behind the jaw or below the ears
    • Cough is sometimes present but not always

    It usually takes 3-4days for the clinical signs to develop after a horse has been in contact with the bacterium, but be aware it can take up to 21days. If you have any concerns with daily temperature checks it is advised to keep your horse(s) in isolation for 3 weeks. A fever is usually the first clinical sign and by monitoring your horse’s temperature closely, you can ensure infection is diagnosed early. This will enable you to take immediate action and to put appropriate biosecurity measures in place.

     

    How does strangles spread?

    Strangles can be passed by direct contact. It is not airborne but it can be dispersed into the environment when the horse coughs or sneezes. Most importantly the bacterium can be spread by indirect contact from stables, paddocks, water tanks, yard equipment, people and vehicles. The bacterium can survive up to 34 days in cool damp conditions and even longer in a water trough. Disinfecting any infected areas, equipment, water troughs and vehicles kills the bacteria effectively.

     

    How is strangles diagnosed?

    If you have any suspicions, then call your vet for advice straight away. A thorough clinical examination will be carried out and appropriate tests will be carried out. There are three sampling methods:

     

    -Blood test: antibodies against strangles can be detected in the blood around 2 weeks after disease exposure. Carrier horses will produce antibodies indefinitely and so blood sampling can detect these hidden sources of infection.

     

    -Swab: swabs can be inserted up the nasal passages close to the opening of the guttural pouch (nasopharyngeal swabs). Swabs can also be used to sample nasal discharge and ruptured abscesses. This method is not very effective at detecting the carriers. Three negative swabs taken at weekly intervals are needed before the horse is considered to be free of infection.

     

    -Guttural pouch endoscopy: a scope (camera) is used to assess the pouches and to take samples directly. If needed saline can be used to flush out infected pus and in some cases chondroids can be retrieved. Chondroids are seen in carrier horses where the pus solidifies in the guttural pouch acting as a continuous source of infection until removed. This is the most reliable method of testing when checking if a strangles case is no longer infectious or to identify a carrier.

     

    How to manage a strangles outbreak?

    The first thing to do is to stop all movement on and off the yard and to isolate any suspicious horses whilst awaiting testing. If strangles is confirmed, your vet will work with you to create a traffic light system.

    -Red zone: strict isolation for confirmed cases or horses displaying strangles signs.

    -Amber zone: strict isolation for horses which may have been in direct or indirect contact with an infected horse during the previous 3 weeks and may be incubating the disease. It is recommended to take temperatures twice daily in order to catch the disease early and to move to the red zone before they start shedding high numbers of bacteria. If all horses in this zone show no signs of infection for 3 weeks after their last contact with an affected horse or are all tested negative then they can move into the green zone.

    -Green zone: close monitoring but normal management of horses having had no contact with sick or at-risk horses for previous 3 weeks. If possible, a designated person will care solely for horses in this zone. They should have no contact with horses in the red/amber zones. If this is not possible then see to the green zone first then the amber and red zones respectively.

     

     

    How to treat horses with strangles?

    The mainstay of treatment is largely supportive care with nursing and close monitoring for any signs of complications. Non-steroidal anti-inflammatories are often prescribed to help with the fever, swellings and pain. Soaking food to aid swallowing and applying warm compresses to developing abscesses to encourage them to burst. Antibiotics are often ineffective but may be indicated in certain cases.

     

    How to prevent strangles?

    -Good yard biosecurity measures and preventative isolation protocols are imperative in preventing outbreaks. An isolation unit can be set up easily and is much more cost effective than dealing with a disease outbreak! Things you may want to include in your isolation unit:

    -Designated area away from other horses and facilities

    -Mark the area with clear signs and barriers

    -Place disinfectant bucket, foot dips and hand sanitisers in the assigned area

    -Overalls, wellies and disposable gloves at the isolation site

    -All equipment (including thermometers) can be stored and used only in the isolation site

    -Bins can be placed to store any rubbish and disposables

     

    Redwings horse sanctuary have been key in gathering all relevant scientific data, working with their vets to produce an informative booklet for both horse and yard owner. You can visit their website for more information and guides on www.redwings.org.uk/strangles.

    If you have any more questions or concerns please don’t hesitate to contact the clinic on 01327 811007 or 01788 523000.