JOHNE’S DISEASE (PARATUBERCULOSIS)

JOHNE’S DISEASE (PARATUBERCULOSIS)

Johne’s Disease (JD) is recognised as an important disease of cattle, sheep, goats, alpacas and deer. It is caused by a bacteria (Mycobacterium. paratuberculosis), and is related to the organism that causes TB.

There are some significant species differences in the pathology of JD. In advanced cases in small ruminants, weight loss and decreased milk and meat production are more common than the chronic wasting and diarrhoea seen in early middle aged cows and sheep. Deer often only show signs of wasting, but in young stock scouring is common and this can be seen in multiply animals at one time.

The incubation period of JD is variable. Some carriers may be infected for life without showing signs. Organisms are excreted in milk, faeces and urine of cattle. Stock can become infected in infancy.

Although clinically affected cattle are usually 2 year olds or older, the clinical disease can show up in deer at an earlier age, Eg as yearlings.

JD is usually diagnosed by finding organisms in the faeces of clinically affected stock or by finding microscopic changes in the intestine of dead animals. It is assumed that all strains are capable of infecting cattle, sheep and deer at least. If you think you may have this condition which will require the collection of laboratory samples, pleasecontact us.

Because of the similarity of microscopic lesions between JD of ruminants and Crohn’s disease of humans, a possible relationship has long been suspected but is as yet unproven.

JD lesions are thought to arise primarily in gut associated lymphoid tissue. It is thought to be acquired by animals whilst young.  Older stock tend to be more resistant to infection.

A vaccine is available for sheep. Special application conditions and registration is required for the use of this vaccine. For more details please contact us