Penicillin is the best antibiotic to treat mice, rats, hamsters, and guinea pigs.

• A. True
• B. False
• C. Depends on the pathogen
• D. Only under supervision

Answer: (B)

Antibiotic choice must fit the species and the infection, not be a single universal best drug. These small herbivorous animals rely on a delicate gut microbial balance, and penicillin can disrupt that balance dramatically, leading to severe diarrhea, enterotoxemia, and even death. Because of this risk, penicillin is generally avoided in guinea pigs, hamsters, and similar species, and isn’t considered the best option for treating infections in them. In mice and rats, the same caution applies: the safest and most effective antibiotic depends on what’s causing the illness and how that drug will affect the animal’s gut and overall health, ideally under veterinary supervision. So the statement isn’t correct.