Which antibiotic is specifically mentioned as being harsh on gut flora in rodents and rabbits?

• A. Penicillin
• B. Amoxicillin
• C. Erythromycin
• D. Tetracycline

Answer: (A)

Penicillin is especially harsh on gut flora in rodents and rabbits because these animals rely on a delicate balance of anaerobic bacteria in the cecum for proper digestion. Penicillin disrupts these beneficial gut microbes, allowing harmful bacteria to overgrow and potentially produce toxins, leading to severe or fatal enterotoxemia. This risk is well known in small mammal care and wildlife rehabilitation, so penicillin is specifically flagged for its propensity to cause gut microbiota disruption in these species. While other antibiotics can also affect the gut, penicillin is the one most commonly associated with this dramatic dysbiosis in rabbits and similar animals, which is why it’s singled out in this context.