What term describes a disease-causing organism?

• A. Pathogen
• B. Symptom
• C. Sanitation
• D. Diagnosis

Answer: (A)

A pathogen is the term for a disease-causing organism. Pathogens include bacteria, viruses, fungi, and parasites that invade a host and disrupt normal body functions, leading to illness. This differs from a symptom, which is what the animal experiences or shows (like coughing or fever). It also differs from sanitation, which are the practices used to reduce exposure and transmission by keeping environments clean, and from diagnosis, which is the process of determining exactly which disease or organism is causing the problem. In livestock practice, knowing the issue is caused by a pathogen helps guide prevention and control measures such as biosecurity, vaccination, appropriate treatment, and sanitation.