When is a culture swab indicated in corneal ulcer evaluation?

• A. If infected, melting, deep, or declining despite treatment
• B. Only if owner requests
• C. Only after surgery
• D. Never

Answer: (A)

A culture swab is indicated when the corneal ulcer shows signs of infection that could progress or resist treatment—infected ulcers with stromal melting, deep involvement, or a decline despite appropriate therapy. In these scenarios, obtaining a culture helps identify the exact organism and its antibiotic sensitivities, allowing targeted therapy that can prevent worsening, perforation, or vision loss. If the ulcer is superficial, non-infected, or responding well to treatment, culture is not routinely needed. Culturing isn’t driven by owner request or by whether surgery has occurred, and it’s not something you would never do.