Strangles In Horses

Understanding Strangles In Horses: Symptoms, Causes, and Treatment Options

Most horses won’t go through their lifetime without facing at least one form of illness. And strangles is a disease that is more prevalent than others. There is a lot of conflicting advice on how horse owners should care for horses that get affected. This advice generally consists of outdated views that surfaced before modern veterinary care.

We take care of a wide variety of horse breeds. We’ve seen our fair share of snots, sneezes, and everything in between. So, let’s discuss strangles and what the symptoms, causes, and treatment options are.

The first thing to do if you suspect strangles, is to not panic. Isolate the horse, clean anywhere it has been or any equipment it has touched and call your vet. Caught early and treated correctly, strangles need not be fatal or even more than just a snotty nose.

What is Strangles In Horses?

Strangles is a clinical disease that mostly affects a horse’s upper respiratory tract. However, if the condition worsens, it can become metastatic strangles (also known as bastard strangles), where other areas of the body are affected.

In most cases, this disease is not life-threatening. Yet, there are a few cases of strangles that have resulted in the mortality of infected horses.

Throughout our experience in handling horses, we’ve seen our fair share of strangles. It affects horses of all age groups but it will be more likely in younger horses due to a lack of exposure in their lifetimes

Especially among these younger horses, strangles is a highly contagious disease. That means it needs to be monitored for the well-being of all equines in your stable.

The strangles bacteria tends to reside in the horses gutteral pouch.

A clear guttral pouch on a horse

During or after a Strangles infection a horse can develop Chondroids inside the gutteral pouch. It is widely belived that these are the cause of horses becoming persistent carriers. The condroids can be identifed by examination with an endoscope, with subsequent removal of the chondroids with a pincer. After removal the pouch is flushed and penicillin can be left in the pouch to clear up any residual bacteria.

Chondroids may have to be removed with an endoscope

Clinical Signs Of Strangles

Depending on the severity of strangles, horses might exhibit these symptoms:

  • Fever/Higher rectal temperature
  • Difficulty eating
  • Nasal discharge
  • Lymph node swelling
  • Lethargy
  • Laboured breathing

Isolating the horse as soon as possible helps prevent the spread of this bacteria to all the horses in your stable.

What Causes Horse Strangles?

Strangles is caused by Streptococcus equi – a type of bacteria that infects lymph nodes. The bacteria can lead to abscess formation and swelling that makes it hard for the horse to breathe and/or eat (which is why this condition is known as strangles).

Strep equi bacteria under the microscope

Strangles bacteria can be contracted through direct horse-to-horse contact or through communal equipment that has been contaminated. And, while it isn’t airborne, it can be spread if a horse coughs or snorts, causing the bacteria to land on other horses or surfaces.

Not all horses have a completely clean bill of health. So, horses that perform in shows or competitions might get exposed. There is also the possibility of some horses being asymptomatic carriers, making it harder to spot before it spreads. This could be a logical explanation for how some healthy horses get strangles.

Treating Infected Horses

So, what is the best course of treatment for sick horses that are manifesting signs of strangles? Well, it’s not a one-size fits all situation. We deal with each horse differently depending on its age and the severity of the infection.

Waiting it out

In most of the instances that we’ve seen infected horses, the infection cleared out on their own over time. Give it about two to three weeks, and some of the clinical signs will subside. Sometimes it might not take the full two weeks, but it is good to watch your horse closely until this period has elapsed.

When waiting for the infection to subside, ensure that the entire herd’s hygiene is of the highest standard. Hygiene in areas like water troughs reduces the infection rate. That’s because there’ll be a lower chance of cross-contamination.

It is important to seek veterinary advice even when you choose to wait for this infection to subside. This will ensure that it’s not another type of infection that’ll increase the risk of significant health complications.


Mild signs of strangles might not need the use of antibiotics but severe clinical signs might need proper medical intervention to help with managing pain and fever. Penicillin, ampicillin, and ceftiofur are antibiotics of choice for this purpose.

The use of antibiotics helps hurry the recovery of young horses – especially those that haven’t developed immunity against this condition. Also, if your equine has difficulty swallowing, antibiotics might make it more bearable to eat and drink fluids.

Be that as it may, other horses might develop post-immune complications. That means they might be susceptible to reinfection later on. This is because certain horses might not have developed immunity like others.

Veterinary care

Sometimes horses might manifest more severe clinical signs that need proper veterinary care. Bastard strangles, for example, may affect lymph nodes in the body. Some cases have been reported in the abdomen, the brain, and the mammary glands of horses.

If the swollen lymph nodes are affecting the upper respiratory tract and are making it hard to breathe, veterinarians could prescribe anti-inflammatory drugs to reduce the swelling. Some cases may need a tracheotomy, but only if the upper respiratory tract is making it exceedingly difficult to breathe.

To flush out abscesses, veterinarians could also use a povidone-iodine solution after they have opened.

Preventing A Strangles Outbreak In Your Stable

As the saying goes, prevention is better than cure. Taking preventative measures to protect horses in your stable is always best. Protecting them from contracting strangles is a great investment for a healthy herd. There are several measures that we take at Strathorn Farm to protect horses from this contagious infection.

You can also adopt some of these preventative measures for your equines. And don’t forget to administer all the needed supplements to boost overall health and wellness.


Using a strangles vaccine has not proven to be very effective. If you do choose to use it, the vaccine should be administered as a precautionary measure to all the horses in your stable. Once horses have strangles diagnosed, vaccination won’t be effective in treating the symptoms.

Vacination takes around three months to help horses reach full immunity. Horses need to get vaccinated three times within three months. After that, a booster shot should be administered every twelve months. Not all horses actuly achieve immunity. For this reason we choose not to do it.

Isolate your herd from other horses

Whether your horse performs at shows or is just used for recreational riding, isolation is the key to prevention. From time to time, horses might be exposed to other horses that you’re not familiar with. The best way to prevent this is to ensure your horses maintain a good distance from others.

The sharing of equipment can also be a point of weakness for strangles to spread, so avoid this as much as you can.

Newly bought horses should be quarantined from the rest of the herd for at least three weeks. This is especially important if a blood test was not conducted when buying the horses.

Note, blood tests wil only show exposure to Strangles bacteria at some point in a horse’s life. It does not mean the horse has an active infection or it is a carrier. It shows antibodies only. A gutteral pouch flush gives a clearer indication of if the horse is a carrier of live strep equi equi bacteria. All horses new to our yard are isolated for three weeks, then checked for chondroids with an endoscope. The gutteral pouch is then flushed and a sample sent to check for live strep equi bacteria. If any is found the horse remains in isolation and is rechecked three weeks later.

The gutteral pouch is located near the back of the jaw. It is accessed with an endoscope through the nose

Also, feeding, grazing, and water supplies should be separated. These could be just as infectious as direct contact between the horses.

Monitoring and testing

Strangles can be monitored by constantly checking the temperature of your horse. A rectal temperature test is one of the ways to do this. We know this process isn’t pretty, but it gets the best results.

Conducting a physical assessment around the lymph nodes on the jawline and the horse’s throat is also crucial. Check if there is any nasal discharge that is a cause of concern on the horse’s nose. Although these aren’t sure-fire ways to diagnose strangles, they are good tell-tale signs for anything that might be amiss.


How would a horse get strangles?

A horse can get strangles from another horse either at the stable or in public or communal areas. Wherever there is a point of contact or proximity to an infected horse, there is a great risk of infection. Even people caring for horses could pass on this condition to other horses. That’s because their hands or clothing might have been exposed to the bacteria.

Is strangles contagious to humans?

Strangles is not contagious to humans. However, it is still very important to practice good personal hygiene when caring for horses with strangles. Avoid touching your mouth, nose, and eyes. Especially after directly handling nasal discharge or abscesses.

Can a horse get strangles if vaccinated?

There are different vaccines for strangles, and they play a crucial role in slowing down the effects of the bacteria. A horse can still get strangles despite getting vaccinated. However, its immune system will be better equipped to deal with the symptoms. So, even if strangles spreads across your stable, the symptoms will be minimal, and the herd will be more likely to have a quick recovery.

Is strangles painful for horses?

Strangles can get excruciatingly painful for some horses. This is mainly due to the swelling and laboured breathing the bacteria causes. In some cases, horses do not eat or drink water due to the pain that strangles causes by the swollen lymph nodes.

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