North American Veterinary Licensing Examination (NAVLE) Practice Test

Immediate antibiotic treatment in a suspected case of strangles can indeed be controversial primarily because it may delay recovery. Strangles, caused by the bacterium *Streptococcus equi*, typically progresses through a clinical course involving an initial incubation period, followed by the development of clinical signs such as fever and swelling of the lymph nodes. In many cases, horses will develop an immune response that can help resolve the infection naturally.

When antibiotics are administered early in the disease process, they can interfere with this natural immune response. The horse may not develop adequate immunity to the pathogen if antibiotics are used too soon, potentially prolonging the infection or leading to complications such as chronic disease. Additionally, antibiotics can change the dynamics of the infection, potentially allowing for persisting carriers or other complications related to treatment.

While the other options touch on valid concerns regarding antibiotic use, they don't capture the core issue as clearly. For instance, while it is true that antibiotics can sometimes lead to adverse reactions or might not work against all bacterial pathogens, the primary concern with strangles specifically is how they may impede the horse's natural healing process and immune response.