Veterinarians determine the appropriate dosage and duration of antibiotic treatment for pets based on several factors, including the type and severity of the infection, the specific antibiotic being used, and the pet’s weight, age, and overall health. Diagnostic tests, such as bacterial cultures and sensitivity testing, help identify the most effective antibiotic. The pet's medical history and any potential for drug interactions are also considered. The dosage is carefully calculated to ensure efficacy while minimizing side effects, and the duration is set to fully eradicate the infection and prevent bacterial resistance. Regular monitoring ensures the treatment's success and adjusts as needed.