About strangles
Strangles is a highly contagious infection caused by a bacteria known as Streptococcus equi that affects the lymph nodes and in severe cases (approximately 1% of cases) can be fatal. Strangles is spread to other horses by direct contact and can also be spread by contaminated food, water, equipment, handlers and their clothing as well as other animals, eg dogs, that may come into contact with the horses. Horses under 5 years of age are more susceptible than older horses and strangles most often occurs when the weather is cold and damp. Once a horse becomes infected with strangles the symptoms usually appear within 7 to 14 days. The bacteria can survive for over a month in water troughs, etc.
Symptoms of strangles
Symptoms of strangles typically include high temperature, inflammation and abscessing of the lymph nodes of the head and/or neck and profuse thick nasal discharge as the abscesses burst and drain. In severe cases the horse may also be distressed, off its feed and wheezing as the inflammation of the lymph nodes can cause the horse difficulty in breathing and swallowing, even crushing the windpipe causing the horse to be strangled in severe cases.
Treatment of strangles
Any horse suspected of suffering from strangles should be isolated from other horses and a veterinarian called immediately. Strangles can be diagnosed by carrying out a blood test. Any other horses that may have had nose to nose contact with the infected horse should also be isolated.
Due to the highly contagious nature of the disease, movement of all horses to and from the premises (including hacking out, etc) should be ceased if any horse on the premises is suspected of suffering from strangles, and certainly once strangles has been confirmed, in order to prevent the disease being spread by the infected horse or other horses on the premises who could be incubating strangles despite not yet showing symptoms.
All equipment should be disinfected and equipment used on horses showing symptoms of strangles should not be used on other horses. A disinfectant foot dip should be placed at the entrance to the premises and used by those entering and leaving the premises.
Handlers of horses suspected or confirmed of suffering from strangles should wash their hands thoroughly in disinfectant after handling to avoid spreading the disease to other horses and should also change clothing before handling other horses.
In many cases strangles can be left untreated and the horse will recover naturally without the need for medical treatment. However, where breathing or swallowing is difficult the vet may administer Penicillin.
In severe cases abscesses may form in the lymph nodes and body organs and cause a condition known as 'bastard strangles'. This can then trigger purpura haemorrhagica that causes bleeding into the gums and organs including the lungs which can be fatal.
Once the symptoms of any horse suffering from strangles has ceased, a further blood test can confirm that strangles is no longer present and provided that within the next 2 weeks no other horse on the premises is displaying symptoms of strangles or is confirmed as suffering from strangles then normal movement of horses to and from the premises can resume.
Prevention of strangles
In order to prevent a horse from being infected with strangles from other horses who may be incubating the disease it is best to ensure the horse does not have close contact with other horses, particularly nose to nose contact, and that equipment is not shared with other horses whilst out at shows, etc. If handling other horses whilst at horse shows, horse auctions, etc hands and footwear should be disinfected and clothing changed afterwards.
