A method for isolating and cultivating the mycobacterium enteritidis chronicæ pseudotuberculosæ bovis, Jöhne, and some experiments on the preparation of a diagnostic vaccine for pseudo-tuberculous enteritis of bovines

The disease of cattle described under the name of pseudo-tuberculous enteritis, or Johne’s disease, is a serious affection which causes considerable losses to farmers and stockowners throughout the British Isles and Europe. Clinically, it is characterised by a slow progressive emaciation and chronic diarrhoea, which causes the milk-yield in cows to fall off, and often ends in death. B. Bang states that some cases show no diarrhoea, though the affected animals die; he also states that the annual losses from this disease on some of the large farms in the Islands of Denmark may amount to 5 to 8 per cent, of the total head of cattle. The disease may affect bovines of all ages (usually from 3 to 6 years, Meissner (33)), but as the period of incubation has been shown to be very long, it is not usually recognised in animals which are less than a year old. It often appears in pregnant cows, and becomes aggravated after calving. On post-mortem examination the lesions are found to be confined to the bowels and the surrounding lymphatic glands. The mucous membrane of the small intestine is seen to be very much thickened—in some cases it may be three or four times the normal. It is thrown into characteristic folds or corrugations, and may show areas of congestion. The large intestine and caecum often present the same lesions. The affected glands are enlarged and oedematous, but show no caseation.