Subclinical diseases are typically diagnosed by which method?

• A. Observation of clinical signs
• B. Laboratory tests
• C. Radiography
• D. Necropsy

Answer: (B)

Subclinical disease is present without obvious outward signs, so you need objective data rather than observable symptoms to detect it. Laboratory tests provide that data by identifying pathogens, immune responses, or early organ dysfunction that isn’t visible clinically. Serology, PCR, culture, and routine hematology or chemistry can reveal infections or abnormalities even when an animal looks healthy, making them the typical method for diagnosing subclinical conditions. Imaging like radiography can help in some cases, but it isn’t the primary tool for detecting subclinical disease and may miss early changes. Necropsy is post-mortem and not used to diagnose living animals.