A zoo veterinarian discovers lethargic animals in the bison and llama pens and a deer found dead; a school group is waiting at the gate. What is the most appropriate initial action?

• A. Let the school group into the zoo, but limit the tour to pens with unaffected animals
• B. Nothing. This disease is unlikely to be spread by zoo visitors
• C. Inform the visitors that the zoo is closed due to illness. You do not want to risk a zoonotic disease spreading to the visitors
• D. Let the school group into the zoo, but do not let them visit the petting zoo

Answer: (C)

When there is a potential infectious disease in animals, the top priority is to protect people and preserve the ability to respond effectively. The sight of lethargic animals in multiple pens plus a dead deer suggests a contagious or zoonotic threat, so the safest first step is to restrict access and pause public activities to prevent exposure while the situation is investigated. Informing the school group that the zoo is closed due to illness helps minimize risk to visitors and allows public health and veterinary authorities to coordinate testing, containment, and communication. Letting people into the zoo, visiting only unaffected pens, or proceeding with any portion of the tour could expose children and staff to possible infection and would hinder outbreak management. Even if the disease isn’t confirmed to spread to humans, shutting down temporarily prevents possible transmission among animals and buys time to implement proper biosafety measures and investigations.