The thought of your horse struggling to breathe due to Strangles is alarming—but respiratory distress isn’t the only symptom of this highly contagious equine disease. Caused by Streptococcus equi equi, Strangles in horses can spread rapidly through barns if not managed properly. Knowing how to identify, treat, and contain Strangles is essential for protecting your horse’s health. In this guide, we cover what Strangles is, early warning signs to watch for, treatment options, and effective steps you can take to reduce or prevent the spread of Strangles in your barn. Stay informed to help keep your herd safe.

The name Strangles has been given because the horse will have difficulty swallowing and breathing. This is all due to the accompanying copious nasal discharge and enlarged lymph nodes in the throat latch area and under the horses chin that are literally blocking your horse’s throat area and pressing on the upper airway.

How is Strangles Transmitted?

Strangles is an infectious disease that’s easily transmitted amongst horses, ponies and donkeys. In fact, it’s an upper respiratory infection caused by a bacteria called Streptococcus equi equi—also known as Strep. Equi.

Strangles is a highly contagious equine disease that spreads rapidly through direct horse-to-horse contact, especially via nasal secretions, coughing, and snorting. One of the most common ways Strangles is transmitted is through nose-to-nose contact, making it critical to avoid allowing horses to touch noses with others. The infectious pus draining from abscesses can also contaminate shared surfaces, equipment, or handlers, further increasing the risk of barn-wide outbreaks. Practicing strict biosecurity is essential to help prevent the spread of Strangles. Thankfully, strangles is not contagious from horses to humans.

Humans can pass this disease from horse to horse by exposing them, inadvertently, via contaminated clothing, grooming supplies, equipment, or hands. Moreover, it can contaminate water and feed sources. In addition, horses can contract it after coming into contact with something as simple as a contaminated surface. Water buckets and moist areas can have viable infective strangles bacteria for up to 4 to 6 weeks, dry items like clothes, fence posts, grooming equipment is infective for up to 3 days.

What are the First Warning Signs of Strangles in Horses?

The early signs of strangles in horses is a fever—a temperature over 100.5 Fahrenheit for adult horses, and 101.5 for foals. Temperatures have been recorded spiking to 107.6 degrees.  It’s a serious matter. Within 24 to 48 hours, they may be lethargic and quite depressed. Along with this you’ll notice that they refuse feed, have a cough with increasing nasal discharge and swollen lymph nodes. The cause of your horse refusing food and water is due to the intense swelling in the throat-latch making it difficult and painful for him to swallow.

What are the Symptoms of Strangles in Horses?

Strangles in horses is a highly contagious disease, with infection rates reaching up to 100% within a herd. While it spreads quickly and produces clear clinical signs, the mortality rate remains low in most cases. The incubation period—the time from exposure to the appearance of symptoms—ranges from 2 to 14 days. Infected horses often develop enlarged lymph nodes within hours, with fever and nasal discharge typically appearing 2 to 3 days after exposure.

Generally speaking, it’s the nasal discharge and swollen lymph nodes that are the most obvious indicators. During the course of the illness the normally clear nasal discharge will become thicker and cloudy. As the disease progresses, your horse may have hard or fluid-filled abscesses forming in and around the throat. And sometimes, abscesses develop around the base of the ear in the location called the guttural pouch.

Swollen lymph nodes in horses with strangles often form abscesses as a result of the body’s inflammatory response to infection. In some cases, the infection spreads to the guttural pouches, which may fill with pus and bacteria. As these abscesses enlarge, they can eventually rupture, causing thick nasal discharge and making it increasingly difficult for the horse to breathe comfortably.

Your horse may hold its head out and down from its body to try to relieve pain in the throat and lymph nodes area in his effort to be able to breathe. He may wheeze and have trouble swallowing. Sometimes abscesses can rupture right through the skin.

It has been seen that some lymph nodes develop to such an obstructive size that your veterinarian may have to perform a tracheotomy. (This is basically a hole in your horse’s neck so that he can breathe). Thankfully, most horses never progress to this point.

In short, not all horses with Strangles will even progress to the stage of abscess involvement. Some will only show signs of lethargy, fever and refuse feed. Up to 40% of horses infected with strangles are asymptomatic carriers (no fevers, no abscess lymph nodes, no large nasal discharges), but they can still drip small amts of bacteria.

Purpura Hemorrhagic as a Result of Strangles

On the other hand, there are horses may develop Purpura hemorrhagic which is a vasculitis caused by the same bacteria. In general horses with Purpura hemorrhagic exhibit mild to severe swelling of their legs, chest area and abdomen. Occasionally you may observe a minor hemorrhage in the gum area and mucus membranes. You may notice that your horse is extremely sore and even be unwilling to move.

Immediate veterinary consultation is required for treating Purpura hemorrhagic. It may involve aggressive anti-inflammatory measures, and possibly corticosteroids. Additionally,  antibiotics may be required if respiratory signs are apparent. Advanced cases often entail longer term therapy.

How is Strangles Diagnosed?

A veterinarian can diagnose Strangles by taking a sample of nasal discharge or pus from an abscess or culturing guttural pouches and sending it for laboratory testing. Common diagnostic methods include bacterial culture and PCR testing to detect the presence of Streptococcus equi equi, the bacterium responsible for the disease.

Strangles has been classified as a reportable disease in all 50 U.S. states since 2017, requiring veterinarians to notify state authorities of confirmed cases. In some instances, affected barns may be placed under quarantine to help control the spread of the disease. Routine bloodwork is typically unremarkable and is not considered a reliable diagnostic tool for strangles. Diagnosis is more effectively made through bacterial culture or PCR testing of nasal or abscess discharge.

What is the Treatment for Strangles?

Lymph node abscesses are typically flushed daily with diluted povidone-iodine solutions until fully resolved. Infected horses are isolated for 14 to 21 days to ensure the infection has cleared before returning to the herd. Antibiotics are generally avoided in cases with draining abscesses, as they can prolong the healing process. However, horses exhibiting severe symptoms such as respiratory distress, loss of appetite, or high fever may receive antibiotic treatment following veterinary evaluation.

A horse suspected to have Strangles should be isolated immediately away from other horses to reduce transmission of the disease. After the horse is isolated, practicing safe and thorough disinfection of anything the sick horse came into contact with is vitally important. Those caring for the sick horse should be mindful to wash their hands thoroughly and change their clothing before handling other horses or products and equipment the non-sick horses are exposed to.

Often, prescription Banamine Paste for Horse is administered to relieve the pain, swelling and to bring down the temperature. Moreover, what a horse needs most is supportive care, including protection from extreme weather, soft food and monitoring of his body temperature. Additionally, if present and if your veterinarian advises, apply hot compresses to the abscesses to encourage them to rupture and drain.

Not all horses with strangles will benefit from antibiotics, unless they have a severe case. Talk to your veterinarian about appropriate treatment methods.

What’s the Short and Long-term Outlook?

Although the disease is quite frightening to observe, most horses do recover in two to four weeks. If a horse develops a complication such as Purpura hemorrhagic, with its accompanying swelling, internal abscesses or other issues, a consult with your veterinarian should be ASAP.

Often, a horse can gain immunity against Strangles after an infection for quite some time, possibly even into years. But, not all horses develop immunity. And some horses continue to shed bacteria through nasal secretions for a long time despite appearing healthy. Warning: These equines can still infect other horses.

Can My Horse Die From Strangles?

Yes, Strangles can be fatal in severe cases. Horses may experience extreme breathing difficulties due to swollen lymph nodes obstructing the airway, which can lead to asphyxiation. Complications such as internal abscesses or a condition known as “bastard strangles” can also increase the risk of death. Prompt veterinary care and proper management are essential for recovery.

How Do I Prevent Strangles From Being in My Barn or Contaminating My Horse?

Using a disinfectant is a critical step in controlling the spread of Strangles in horses. Products like Virkon™ S Disinfectant & Viruscide are highly effective in killing the Streptococcus equi equi bacteria that cause Strangles. This powerful disinfectant can be used to clean stalls, tack, buckets, trailers, and any surfaces that may have come into contact with an infected horse. Regular disinfection helps break the cycle of transmission, protecting other horses from exposure. Always follow label directions for proper dilution and contact time to ensure maximum effectiveness. Maintaining strict hygiene and thorough disinfection practices is key to managing and preventing Strangles outbreaks.

Practicing good equine biosecurity is also essential for reducing the risk of disease transmission, including highly contagious illnesses like Strangles. One of the most effective steps is to avoid sharing equipment such as brushes, halters, water buckets, or feed tubs between horses—especially if a horse is new to the property, returning from travel, or has an unknown health history. Isolating new arrivals for a period of time allows you to monitor for symptoms and helps prevent the introduction of infectious diseases to your herd. In addition, all surfaces, especially those that come into contact with nasal secretions or pus from abscesses, should be scrubbed with soap and water, then thoroughly disinfected. Water buckets and troughs are key areas to clean and sanitize, as they can easily harbor bacteria and facilitate the spread of illness. Implementing consistent cleaning protocols and maintaining isolation practices are essential components of a strong biosecurity plan for every horse facility.

In addition, new horses coming into a barn need to be quarantined for 14 to 21 days to see if signs of strangles prior to joining herd.

Is There a Vaccine for Strangles in Horses?

Yes, vaccines for Strangles are available and can help reduce the risk and severity of infection. Options like Strepvax II provide protection, but no vaccine offers 100% immunity for every horse. It’s important to consult your veterinarian to determine whether vaccination is appropriate for your horse based on age, exposure risk, and overall health.

Protect Your Herd: What Every Horse Owner Should Know About Strangles

Equine Strangles is a serious and highly contagious disease that can quickly spread through a barn if not managed properly. While most horses recover with supportive care, the illness can cause significant discomfort, complications, and—in rare cases—be fatal. Recognizing the symptoms early, isolating affected horses, practicing strict biosecurity, and discussing vaccination options with your veterinarian are all essential steps in protecting your herd. By staying informed and prepared, you can help reduce the risk of strangles and safeguard your horse’s health.