Strangles in Horses: Signs, Quarantine, and Recovery

Quick Answer
  • Strangles is a highly contagious bacterial infection caused by Streptococcus equi subspecies equi that commonly causes fever, thick nasal discharge, and swollen lymph nodes under the jaw or throatlatch.
  • Isolate any horse with fever, nasal discharge, or enlarged lymph nodes right away and contact your vet before moving that horse on or off the property.
  • Many uncomplicated cases improve with supportive care, but some horses need antibiotics, drainage of abscesses, guttural pouch treatment, or hospital care if breathing or swallowing becomes difficult.
  • Recovered horses may keep shedding bacteria for about 4 to 6 weeks, and some become longer-term carriers, so quarantine should continue until your vet confirms testing is negative.
  • Typical US cost range in 2026 is about $300-$1,200 for farm exam, testing, and basic supportive care, with more complex cases ranging from $1,500-$6,000+ if endoscopy, repeated lavage, or hospitalization is needed.
Estimated cost: $300–$6,000

What Is Strangles in Horses?

Strangles is a contagious bacterial disease of horses caused by Streptococcus equi subspecies equi. It mainly affects the upper respiratory tract and nearby lymph nodes, especially the nodes under the jaw and around the throatlatch. These lymph nodes often become enlarged, painful, and may form abscesses that eventually rupture and drain.

The disease spreads easily in barns, boarding facilities, show grounds, and other places where horses have close contact or share water, equipment, or handlers. Young horses are often affected, but horses of any age can become infected.

Many horses recover well with time and supportive care. Still, strangles can become more serious when swelling interferes with breathing or swallowing, when infection spreads deeper into the body, or when a horse becomes a silent carrier in the guttural pouches. That is why early isolation, testing, and a clear barn biosecurity plan matter so much.

Symptoms of Strangles in Horses

  • Fever, often the earliest sign
  • Thick nasal discharge, often yellow or pus-like
  • Swollen or painful lymph nodes under the jaw or at the throatlatch
  • Abscesses that may soften, rupture, and drain
  • Low appetite, lethargy, or reluctance to eat because swallowing hurts
  • Coughing or noisy breathing
  • Trouble breathing or trouble swallowing from severe swelling
  • Leg, head, or belly swelling; pinpoint red spots on gums; or signs of colic or neurologic disease in rare complications

Fever often shows up before the classic swollen lymph nodes and nasal discharge. In a barn outbreak, a horse with a new fever may be contagious before obvious abscesses appear.

See your vet immediately if your horse has trouble breathing, cannot swallow normally, stops eating or drinking, develops marked swelling of the head or limbs, or shows signs of colic, weakness, or neurologic changes. These can point to complications such as airway obstruction, purpura hemorrhagica, or metastatic infection.

What Causes Strangles in Horses?

Strangles is caused by the bacterium Streptococcus equi subspecies equi. The bacteria spread through direct horse-to-horse contact and through contaminated hands, clothing, buckets, tack, lead ropes, trailers, stalls, and shared water sources. Flies may also move bacteria mechanically during outbreaks.

A horse can be exposed at home, during travel, at shows, sales, clinics, or any setting where horses from different groups mix. New arrivals and recently traveled horses are common sources of introduction into a stable.

One of the biggest challenges is the carrier horse. Some horses look normal after recovery but continue to harbor bacteria, often in the guttural pouches, and can keep infecting others. Because of that, a horse that seems fully recovered may still need follow-up testing before returning to the group.

How Is Strangles in Horses Diagnosed?

Your vet will start with a physical exam, temperature history, and the pattern of illness in the barn. Strangles is often suspected when a horse has fever, nasal discharge, and enlarged lymph nodes, but testing is important because other respiratory diseases can look similar early on.

Diagnosis is usually confirmed with bacterial culture or PCR testing. Samples may come from draining abscess material, a nasopharyngeal wash, or a guttural pouch wash. PCR is widely used because it is sensitive and fast, while culture can help confirm live bacteria.

If your vet is checking whether a horse is still shedding after recovery, guttural pouch endoscopy with lavage and PCR is often the most sensitive approach. When that is not practical, some horses are cleared with a series of negative nasopharyngeal washes collected over time. This matters because quarantine decisions should be based on testing, not appearance alone.

Treatment Options for Strangles in Horses

Spectrum of Care means you have options. Here are treatment tiers at different price points.

Budget-Conscious Care

$300–$900
Best for: Uncomplicated cases in stable horses that are eating, breathing comfortably, and can be managed safely at home with strict quarantine.
  • Farm call and physical exam
  • Isolation and barn biosecurity plan
  • Twice-daily temperature monitoring
  • Anti-inflammatory medication if your vet recommends it
  • Soft feed, hydration support, rest, and warm compresses to encourage abscess maturation
  • Basic drainage care for ruptured abscesses under your vet's guidance
  • Targeted testing only if needed to confirm the outbreak
Expected outcome: Good for many uncomplicated cases, though recovery can still take several weeks and follow-up testing may be needed before release from quarantine.
Consider: Lower upfront cost range, but less intensive testing can make it harder to identify carriers early. Some horses later need additional visits, PCR testing, or guttural pouch evaluation.
Most Common

Recommended Standard Treatment

$900–$2,500
Best for: Most horses with suspected or confirmed strangles, especially when a barn outbreak needs organized diagnosis, treatment planning, and safe release from quarantine.
  • Farm or clinic exam plus CBC or other baseline lab work as indicated
  • PCR and/or culture from abscess, nasopharyngeal wash, or nasal sample
  • Supportive care with anti-inflammatories, nutrition, hydration, and abscess management
  • Antibiotics when your vet feels they are appropriate, such as early disease, severe fever, dysphagia, dyspnea, or other complicated presentations
  • Structured quarantine with separate equipment and caretaker flow
  • Recheck exams and testing to guide return-to-barn decisions
  • Follow-up carrier screening after clinical recovery
Expected outcome: Good in most horses when complications are avoided and carrier status is addressed. Recovery is often straightforward after abscesses drain and the horse regains appetite and comfort.
Consider: Higher cost range than conservative care, but usually gives clearer answers for treatment and biosecurity. Antibiotic decisions must be individualized because timing can affect immunity and case management.

Advanced / Critical Care

$2,500–$6,000
Best for: Horses with breathing difficulty, trouble swallowing, prolonged high fever, severe lethargy, poor intake, guttural pouch disease, or suspected systemic complications.
  • Referral hospital care or intensive on-farm management
  • Endoscopy of the upper airway and guttural pouches
  • Guttural pouch lavage and treatment for empyema or chondroids
  • IV fluids, injectable medications, and close monitoring
  • Ultrasound or additional imaging for deeper abscesses or metastatic disease
  • Airway support, including temporary tracheostomy if severe swelling obstructs breathing
  • Management of complications such as purpura hemorrhagica, myositis, or bastard strangles
Expected outcome: Variable. Many horses still recover well with timely care, but prognosis depends on the complication, how quickly treatment starts, and whether internal abscesses or immune-mediated disease are present.
Consider: Most intensive and highest cost range. It offers the broadest diagnostic and treatment options, but may require transport, hospitalization, and repeated procedures.

Cost estimates as of 2026-03. Actual costs vary by location, clinic, and individual case.

Questions to Ask Your Vet About Strangles in Horses

Bring these questions to your vet appointment to get the most out of your visit.

  1. Based on my horse's signs, how likely is strangles compared with other respiratory infections?
  2. What sample do you recommend for testing right now: abscess material, nasal or nasopharyngeal wash, or guttural pouch wash?
  3. Does my horse need supportive care only, or are there signs that make antibiotics appropriate in this case?
  4. How should I separate sick, exposed, and healthy horses on this property?
  5. What disinfectants and cleaning steps do you want us to use for buckets, stalls, tack, and shared equipment?
  6. When should we start follow-up testing to check whether my horse is still shedding bacteria?
  7. What signs would mean my horse needs emergency care, such as trouble breathing, trouble swallowing, or severe swelling?
  8. Should any horses on this farm be vaccinated later, after the outbreak is over and testing is complete?

How to Prevent Strangles in Horses

Prevention starts with biosecurity. New arrivals should be separated from resident horses for about 14 to 21 days, and many equine guidelines recommend a full 3-week quarantine with temperature monitoring. Horses returning from shows, sales, or clinics may also need temporary separation before rejoining the group.

During an outbreak, horses should be divided into affected, exposed, and clean groups. Use separate buckets, tack, thermometers, and handlers when possible. Clean organic debris first, then disinfect equipment and surfaces as directed by your vet. Care for healthy horses first and sick horses last.

Testing matters because outward recovery does not always mean the horse is no longer contagious. Many horses shed for about 4 to 6 weeks after recovery, and a smaller number become longer-term carriers, often in the guttural pouches. Your vet may recommend guttural pouch endoscopy and PCR, or a series of negative nasopharyngeal washes, before ending quarantine.

Vaccination can be part of prevention for some barns, especially those with recurring risk or frequent horse movement, but it is not the right fit for every horse or every moment. Vaccination is generally not recommended in the middle of an active outbreak or for horses with recent direct exposure unless your vet advises otherwise. A risk-based plan with your vet is the safest approach.

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