If an animal is exposed to rabies and owners are unable to provide proof of vaccination, serological monitoring can be performed, but must be done when?

• A. Within 24 hours of exposure
• B. Within 2 weeks of exposure
• C. Within 96 hours of exposure
• D. Only after vaccination is administered

Answer: (C)

Serological monitoring after rabies exposure is used to check whether an animal already has protective rabies antibodies when vaccination status is uncertain. To make that measurement meaningful, it must be done very soon after exposure—within 96 hours—so that the results reflect the animal’s baseline immunity at the time of exposure and are not confounded by antibodies produced in response to any post-exposure vaccination. If testing is delayed beyond this window, a vaccination given after exposure could raise antibody levels and obscure whether the animal had protective immunity originally. The other timeframes would not reliably distinguish pre-existing immunity from vaccine-induced antibodies, so the within-96-hours window is the appropriate timing.