What is the appropriate treatment for Streptococcus equi infection, commonly known as strangles?

• A. Amoxicillin
• B. Trimethoprim-sulfadiazine
• C. Penicillin or nothing
• D. Ciprofloxacin

Answer: (C)

Streptococcus equi (strangles) is highly susceptible to penicillin, so it is the treatment of choice when antibiotics are indicated. Administering penicillin G during the acute phase helps reduce fever, shorten illness, and lower bacterial load, which can also lessen nasal shedding and spread. If you choose not to use antibiotics, management focuses on isolation, supportive care, and draining abscesses as needed; antibiotics are reserved for horses showing systemic illness or severe illness where therapy will make a difference. Other antibiotics do not provide the same reliable efficacy for strangles, and options like oral amoxicillin, trimethoprim-sulfadiazine, or fluoroquinolones are not considered first-line. Therefore, penicillin is the best-supported treatment when antibiotics are used, or no antibiotic therapy is chosen if the case is mild.