is chronic infection of intestine caused by Mycobacterium
Nursing of calf by infected dam
Contaminated feed and water
Also transmitted from dam to fetus and also present in
Most important is infection occurs under thirty days of age and
incubation period is very long so clinical signs appear at 3-5
years of age.
Stage one is silent stage in which no clinical signs and it
occurs in younger animals.
In subclinical stage animal becomes carrier and potential source
of infection. It is at adult stage.
In clinical stage chronic diarrhea with presence of air bubbles
and no odour, feed intake is normal, all other parameters normal
but more thirst.