In most cases of Johne's disease, serology is most likely to detect an infected animal during later stages of the infection when antibody is most likely to be produced. Shedding In the context of paratuberculosis biology, shedding usually refers to the excretion of M. paratuberculosis in feces, milk or semen. Animals in the more advanced stage of the infection become fecal shedders. Sign Signs of disease are manifestations caused by the infection that can be observed. Examples, diarrhea and weight loss are signs of Johne's disease.
Signs are distinct from symptoms.
The sub-clinical phase of paratuberculosis in cattle can last 1 to 10 years. Symptom Symptoms are subjective evidence of disease. Humans can describe feelings they have of being sick that are not obvious to an observer. An example is the feeling of aching muscles and joints that come with the flu are symptoms. This defines the outcome of a diagnostic test.