Understanding Strangles in Horses: Symptoms, Prevention, and Management

Strangles, a highly contagious respiratory infection caused by the bacterium Streptococcus equi, presents a significant threat to equine health worldwide. Recently, a 13-year-old Paint mare in Ontario's United Counties of Leeds and Grenville was diagnosed with strangles, drawing attention to the ongoing risks this disease poses to horse populations.

What is Strangles?

Strangles affects horses, donkeys, and ponies of all ages, breeds, and sexes. The infection targets the lymph nodes around the jaw, causing swelling that can severely interfere with breathing—hence the name ‘Strangles’.

Clinical Signs and Symptoms

The symptoms of strangles can vary widely among horses. However, common clinical signs include:

  • Depression and Loss of Appetite: Infected horses often exhibit lethargy and a reduced appetite.
  • Raised Temperature: Fever is a common early sign.
  • Cough and Nasal Discharge: Thick, yellowish nasal discharge often accompanies a cough.
  • Swollen Lymph Nodes: Enlarged lymph nodes around the throat area are a hallmark symptom.
  • Pus Drainage: Abscesses forming and draining pus from lymph nodes in the jaw region.

Transmission and Contagion

Strangles is highly contagious, spreading rapidly through direct horse-to-horse contact or contaminated feed, water, and equipment. The bacteria can survive in water for up to four weeks, making biosecurity measures crucial to prevent outbreaks.

Diagnosis

Diagnosing strangles typically involves:

  • Nasopharyngeal Swabs: PCR testing of nasal swabs or washes.
  • Blood Tests: To identify infected horses and asymptomatic carriers.
  • Guttural Pouch Endoscopy: Visualizing the inside of the guttural pouch to take samples for testing.

Treatment and Recovery

Treatment for strangles usually focuses on supportive care:

  • Anti-inflammatory Medication: To manage fever and discomfort.
  • Dietary Adjustments: Feeding wet, sloppy food can make swallowing easier.
  • Hot Compresses: To help abscesses drain.
  • Isolation: Infected horses must be isolated to prevent the disease's spread.

Most horses recover within three to four weeks, although some may become carriers, harboring the bacteria in their guttural pouches and intermittently spreading the disease.

Complications and Long-term Consequences

While most horses recover, strangles can lead to severe complications:

  • Bastard Strangles: Abscesses develop in other body organs, which can be fatal.
  • Purpura Haemorrhagica: A rare but potentially life-threatening condition causing bleeding and fluid accumulation in the limbs and head.

Prevention and Biosecurity

Preventing strangles outbreaks heavily relies on good yard management and biosecurity practices:

  • Quarantine New Arrivals: Isolate new horses for at least two weeks before introducing them to the main herd.
  • Hygiene and Disinfection: Regularly clean and disinfect surfaces, equipment, and water sources.
  • Vaccination: A submucosal vaccine is available for at-risk horses, though its effectiveness varies, making biosecurity measures essential.

The Role of the Equine Disease Communication Center (EDCC)

The EDCC plays a vital role in managing and preventing equine infectious diseases like strangles by disseminating verified disease reports. This independent nonprofit organization, supported by industry donations, provides open access to information, aiding in the control and prevention of equine health issues.

Conclusion

Strangles remains a significant health risk for equine populations, necessitating vigilant biosecurity measures and prompt diagnostic and treatment protocols. Understanding the disease's transmission, symptoms, and prevention strategies is crucial for equine owners and caretakers. By combining effective biosecurity practices with the support of organizations like the EDCC, the spread of strangles can be effectively managed and controlled.

Source: [The Horse](https://thehorse.com/)