Therapeutic antimicrobial use should be confined to appropriate clinical indications.

• A definitive diagnosis that indicates antimicrobial therapy is appropriate should be established whenever possible, and empirical use of antimicrobials should be avoided.
• Practitioners should strive to rule out viral infections, parasitism, mycotoxicosis, nutritional imbalances, neoplasia, and other ailments that will not respond to antimicrobial therapies.
• Antimicrobial therapy is not indicated in most upper respiratory infections (e.g., feline herpesvirus or calicivirus and canine infectious respiratory disease complex) not suspected to be complicated by secondary bacterial infection.
• Most cases of pancreatitis in dogs and cats are not associated with bacterial infection.
• Most cases of feline lower urinary tract disease do not involve bacterial infection, particularly in cats younger than 10 years of age, and in such cases, antimicrobials are not indicated.
• Systemic antimicrobials are usually not indicated for routine dental prophylaxis or after tooth extractions. In cases of periodontitis, systemic antimicrobials are not a substitute for surgical treatment. In most cases of periapical tooth root abscesses, debridement of infective tissue is sufficient to control infection.⁹
• Most cases of acute diarrhea are not due to pathogenic bacterial infections or are self-limiting, so antimicrobials are not indicated, do not hasten time to clinical resolution, and may cause further dysbiosis.^10–13