Strangles qPCR
About the Test The qPCR test detects the genome (DNA) of Streptococcus equi subspecies equi, the pathogen responsible for Strangles....
€45.00
Sample Requirements
- Nasopharyngeal swab - dry swab (see AAEP guidelines)
- Nasal swabs or draining lymph nodes
- Guttural pouch washes
Send your sample by regular mail or express delivery to:
Equigerminal Lab HIESE
Rua da Quinta do Sobreiro Nº25
3230-343 Penela, Portugal
Turnaround Time
2 to 5 working days
About the test
The bacterial culture detects viable Streptococcus equi subspecies equi, the bacterium responsible for Strangles. Isolation of the organism confirms active infection and supports disease diagnosis and outbreak management.
Why test?
Testing is recommended to:
- Confirm Streptococcus equi infection in horses with suspected Strangles.
- Detect infection during the early stages of disease.
- Investigate respiratory disease outbreaks.
- Identify carrier horses shedding the bacterium.
- Support rapid treatment decisions and biosecurity measures.
How it works
🛒 Purchase the Test: Select and buy the test online.
📧 Receive Instructions: After payment confirmation, receive instructions for sample collection.
✨ Sample Collection: Your veterinarian collects the appropriate sample (nasopharyngeal swab, nasal swab, draining lymph node swab or guttural pouch wash).
📄 Download Submission Form: Download the printable submission form.
📮 Send Samples: Send your samples by regular mail or express delivery to:
Equigerminal Lab HIESE
Rua da Quinta do Sobreiro Nº25
3230-343 Penela, Portugal
📄 Receive Results: Get your laboratory report by email.
Clinical signs
- Classic clinical signs include a fever (often >103°F or 39.5°C) first, followed by one or more of the following symptoms: depression, thick nasal discharge, and lymph node enlargement under the jaw and/or in the throat latch region. The abscessed lymph nodes may drain externally or into the guttural pouches (blind-end sacs connected to the throat in horses) resulting in nasal discharge. Horses that have been vaccinated for strangles or horses that have previous partial immunity may develop milder signs of upper respiratory tract infection.
- Bastard strangles cases may develop colic signs, fever, and/or weight loss with or without a history of previous strangles disease or exposure. Horses with purpura hemorrhagica may develop edema of the head, trunk, and/or legs, and broken blood vessels or bruising of the mucous membranes of the mouth, eyes, and nose. Additional signs can include fever, severe depression, and muscle tightness. The severity of symptoms in purpura hemorrhagica cases ranges from mild to life-threatening.
Transmission
- Strangles is caused by oral exposure of a horse to S. equi bacteria. Once within the oral cavity, the bacteria invade the tonsils and subsequently colonize the lymph nodes.
- Bacteria can be transmitted through contact with pus or nasal discharges from an infected horse, or from contaminated bedding or barn equipment (water troughs, buckets, etc.).
- Flies may also act as vectors, spreading the bacteria from horse to horse.
- Under the right conditions, S. equi can survive in the environment for weeks or months.
- Exposure of a horse to S. equi does not necessarily mean that it will come down with strangles. Factors that influence the risk of disease include dose of bacteria (poor sanitation and direct contact with nasal secretions and pus increase the chance of disease); immune status of horse. Previously exposed horses are often immune to the disease, or do not get as sick as unexposed horses. During the first three to six months of life, foals are often protected by maternal antibodies. Vaccination can also increase resistance to the disease; stress (poor nutrition, overcrowding, lengthy transportation, or pre-existing diseases increase the risk of strangles).
- Strangles may be transmitted by “silent shedders” who do not display signs of disease. These horses commonly carry the strangles organism in the guttural pouch, an air sac at the back of the horse’s throat. Detection of these animals requires guttural pouch endoscopy (passing an endoscope via the horse’s nose into the guttural pouch). Strangles is most commonly transmitted by acutely ill or recovering horses that are still shedding bacteria in their nasal secretions. Bacterial culture results have a turnaround time of 2 to 3 days. The DNA test known as Polymerase Chain Reaction (PCR) takes less than a day. However, it may take an additional 1 to 2 days to send samples to the laboratory.
Prevention
- Biosecurity on the farm is necessary to prevent the spread of disease.
- Isolate new horses for three weeks prior to introducing them to the rest of the population.
- Isolate any horse with a fever and signs of strangles.
- Do not share tack or equipment between sick horses and others.
- Perform twice daily monitoring of rectal temperatures of all horses in an outbreak to identify new cases.
- Stop all movement of horses to and from the farm when strangles is identified.
- Disinfect water buckets daily.
- Use strict hygiene between horses to reduce the spread of the disease.
- Ideally, three throat flush samples are obtained from recovering horses and any horses who were in contact with sick horses at approximately weekly intervals and tested for S. equi subsp equi by PCR and culture. Identification of strangles bacteria in clinically recovered horses may mean the guttural pouches have retained some infection. Endoscopy of the guttural pouches provides visualization of any pus or dried debris (chondroids) that harbor the bacteria. A small number of horses will recover from strangles and continue to shed bacteria from the guttural pouch, causing recurrent farm outbreaks. Detection and treatment of these “silent carriers” (S. equi bacteria in guttural pouches) via endoscopy and PCR is essential for preventing disease recurrence on a farm.
- Discuss vaccination types and recommendations with your veterinarian. Vaccination does not provide 100% immunity against S. equi infection. Vaccination is not recommended during or within two years of a strangles outbreak due to the increased risk of purpura hemorrhagica.
Results
The qPCR test reports one of the following:
- Detected: Streptococcus equi DNA was identified in the submitted sample, indicating the presence of the bacterium.
- Not Detected: No Streptococcus equi DNA was detected.
Results should always be interpreted together with the horse's clinical signs and veterinary examination.
Additional information
qPCR is a rapid and highly sensitive method for detecting Streptococcus equi DNA. It can identify infected horses earlier than bacterial culture and is particularly useful during outbreaks and for detecting asymptomatic carrier animals.
FAQs
Which horses should be tested?
Horses showing fever, nasal discharge, swollen lymph nodes or other signs consistent with Strangles, as well as horses involved in disease outbreaks or carrier investigations.
Which samples are accepted?
Nasopharyngeal swabs, nasal swabs, draining lymph node swabs or guttural pouch washes.
Can healthy horses carry Streptococcus equi?
Yes. Some horses become asymptomatic carriers and may continue to shed the bacterium from the guttural pouches after clinical recovery.
When will I receive my results?
Results are available within 2 to 5 working days after sample arrival at the laboratory.