An animal meets an infection, makes antibodies to it and recovers with no permanent side effects. For example an animal could become infected by BVD after an outing, the animal mounts an immune respon [..]

Johnes Disease (paratuberculosis) also known as MAP (the infectious organism) is a chronic infectious bacterial enteritis that results in persistent diarrhoea, progressive wasting and eventual death. [..]

Glossary of health terms : ACCREDITED -

 Immune substances produced in response to an infection or vaccination or acquired as in colostrum or antisera. ANTIGENS -

 Serum containing antibodies to a particular disease or diseases which when administered to an animal provides it with temporary immunity. BIOSECURITY -

 Bovine Viral Diarrhoea (see Part 1). CARRIER - 

 Immunity, which is dependent on the sensitisation of certain white blood cells, rather than antibodies. CHeCS -

 A herd into which no animals are imported; truly closed herds must not have any biological contact with other herds. This includes never bringing leased animals onto the property, not using bought in [..]

When an animal may be infected with two or more infections at the same time. D.N.A. - 

 Divisional Veterinary Manager to whose office all incidents of notifiable diseases should be reported. ENCEPHALOPATHIES -