Strangles is a highly contagious infection, typically occurring in the upper airway and lymph nodes of the head and neck. It is caused by the bacteria Streptococcus equi. Younger horses are especially susceptible, and the bacteria has the ability to recur on farms due to a previous outbreak. Vaccination may help prevent strangles, but it is not a guarantee. However, a vaccine may reduce the severity of the disease during an outbreak. Veterinarians can determine which horses may need or benefit from the vaccine.

Clinical signs of strangles include:

• Anorexia
• Depression
• Difficulty swallowing
• Fever
• Enlarged retropharyngeal lymph nodes (behind the throat latch area)
• Enlarged submandibular lymph nodes (may abscess and drain pus if disease progresses)
• Guttural pouch infection and pus accumulation
• Nasal discharge

Diagnosis of strangles can be confirmed by your veterinarian performing a bacterial cultural from nasal discharge or abscess, a testing for the presence of the organism using PCR. It is important to test all horses, as some horses may carry the bacteria and not show any symptoms. Treatment of strangles is determined by the severity of the disease and the age of the horse. Treatment usually involves anti-inflammatories, but in some cases may include antibiotics.