What is the most appropriate antibiotic for treating myonecrosis caused by Clostridium perfringens in horses?

Myonecrosis caused by Clostridium perfringens is a serious condition in horses, often associated with tissue necrosis due to the production of toxins by this bacterium. The most appropriate antibiotic treatment specified in this scenario is penicillin.

Penicillin has proven effectiveness against Clostridia species due to its ability to inhibit bacterial cell wall synthesis. Clostridium perfringens is sensitive to penicillin, and its use can help control the bacterial proliferation and mitigate the severe effects of myonecrosis. Administering penicillin as part of the treatment protocol can significantly aid in reducing the bacterial load in affected tissues, thereby improving the overall prognosis for the horse.

Other antibiotics mentioned, while useful for various infections, are not the first-line treatment against Clostridium perfringens. Cloxacillin, a beta-lactam antibiotic, has limited effectiveness against anaerobic bacteria such as Clostridia. Gentamicin is more effective against aerobic gram-negative bacteria and is not typically used for anaerobic infections like myonecrosis caused by Clostridium. Rifampin, while it has some activity against certain bacteria, does not provide the necessary coverage and efficacy against Clostridium perfringens specifically in this condition. Thus