Strangles is a highly contagious disease that affects a horse’s lymph nodes in its upper respiratory tract. It is caused by bacteria called Streptococcus Equi. It got the name strangles from the infection narrowing the horses breathing tubes making gasping sounds when your horse breaths. This is caused by the enlarged lymph nodes around the jawbone.
The Signs and Symptoms
The first signs and symptoms of strangles are high fever, poor appetite and depression. Your horse will also have a thin watery discharge from his nose. Quickly this discharge changes to a thick and yellow one.
Your horse’s lymph nodes around his neck and throat become enlarged. They will be most noticeable between his jaw bones. These can even abscess into pus leaking sores which drain out from underneath his jaw. Although not usually fatal, it certainly can be.
Strangles can affect horses at any age, however the younger horses, under 5 years old are most affected. It is caught after exposure to another horse that is infectious which can be before and after symptoms occur. The spread is commonly when a new horse is added to the herd. Around 20% of horses are still contagious for a month after all symptoms vanish.
How it is Transferred
Although mostly the bacterium is spread by nose to nose contact it can also be spread by contaminated equipment. It is important to properly clean gear, buckets, stalls and water troughs. Fortunately the bacteria die fairly quickly when they are outside of the horse’s body.
Following being exposed to the strangles bacteria, if infected your horse will begin to get symptoms after two to six days. Lymph nodes will abscess one to two weeks after symptoms appear if left untreated.
The pus coming from these abscesses is highly contagious.
Most horses will recover, however around ten percent of untreated horses will die, usually from a secondary infection which causes pneumonia.
On the rare occasion the abscesses will spread to other areas of the body such as the lungs, internal organs and even your horse’s brain.
What to Do About It
The treatment of the disease depends on where in the illnesses progression your horse is when treatment is sought. So get in touch with your vet quickly if you suspect that your horse has had exposure to strangles.
To protect your herd isolate new horses for four to six weeks before adding to your other horses. Three nasal swabs over seven days are required prior to giving your horse the all clear.
Strangles can also be controlled by vaccinations. Although the effectiveness is increasing and side effects of these modern vaccines are decreasing, they do not fully prevent your horse from catching strangles once they are exposed to the bacteria.
Your horse cannot contract strangles from the vaccine as only completely damaged parts of the bacteria are used to get an immune response from your horse.
If you suspect your horse has been exposed to strangles or to be coming down with some respiratory symptoms, contact your vet immediately. The sooner you begin your horse on antibiotics the less chance your horse will suffer and die.
However, once lymph nodes have enlarged and become abscessed, antibiotic treatments will only prolong the horse’s illness. It is better to allow the abscess to open, or to have your vet lance them so they can then drain. Next you will need to flush the drainage site and keep it as clean as possible and maintain strict isolation.
If you know your horse has been exposed to a horse with strangles but they are not yet symptomatic, then give antibiotics for a week after the exposure. However, with prolonged exposure from a herd or stable mate then antibiotic will do little to prevent infection.