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

Strangles, caused by Streptococcus equi, is a highly contagious disease affecting horses and is characterized by fever and swelling of the lymph nodes, particularly those around the throat. The appropriate treatment for this infection primarily depends on the stage of the disease and the clinical signs present.

In cases of strangles, the use of antibiotics can be controversial, especially if administered too early in the disease process. In many situations, supportive care and symptomatic treatment (such as hot packing of abscesses and perhaps anti-inflammatory medications) are preferred. However, if antibiotic treatment is warranted, penicillin is the first-line choice due to its effectiveness against Streptococcus equi.

Using penicillin helps to reduce the duration of the infection and alleviate the symptoms. Importantly, it is generally avoided to treat cases of strangles in the early stage with antibiotics indiscriminately, as this could potentially lead to complications, such as the development of a more severe form of the disease.

When considering the other options, while amoxicillin and trimethoprim-sulfadiazine are antibiotics that can be used in different infections, penicillin is specifically tailored for Streptococcus equi. Ciprofloxacin is generally not recommended for strangles. Therefore, the