04/08/2022
So, let’s talk about ‘Strangles’ – including testing
‘Strangles’ = name for infection with bacteria Streptococcus equi equi (S equi equi).
Strangles is extremely contagious, spreading through a population rapidly. Although clinical signs are very unsightly and distressing to experience, it has a low mortality rate if veterinary attention is sought early.
Clinical signs include:
• High temperature (38.6-41oC)
• Thick white/yellow nasal discharge, sometimes being bloody
• Behaviour – Depressed/quiet/unresponsive or dull
• Enlarged swellings around the jaw and neck
• Lowered head, coughing
In some cases, the swelling behind the jaw (in the retropharyngeal lymph nodes) can block the airways. These cases require emergency treatment, sometimes even a life-saving tracheotomy to keep the airways open.
Clinical signs occur 3-14 days after the horse has been infected. Treatment involves strict isolation, maturation of the abscesses using hot compression, and lancing them surgically. Once opened, they require daily flushing. Antibiotics are rarely used (except in the most extreme of circumstances) - they slow down maturation of the abscesses and prolong the infection. Anti-inflammatories are essential to reduce temperature, swelling, and help the horse feel better.
Chronic carriers - Roughly 10% of infected horses become carriers, who continuously shed the bacteria and are very infectious to all other horses. These are treated by direct endoscopic flushing of the guttural pouches with antibiotics, where the bacteria live.
Movement testing – Blood tests (such as a ‘serum ELISA antibody test’) tell us whether there is a likelihood that your horse has come into contact with the bacteria within the last 6 months. If the result is very high, or increases on the second test in 2 weeks, there is a possible active infection. Although useful in assessing risk of an active infection, it is not foolproof. The most accurate test for strangles is to endoscopically flush the guttural pouches with saline, and assess the fluid in the lab for the bacteria directly.
If you are concerned your horse may have Strangles, please contact Stride Equine Vets for a consultation.