Chronic bacterial dysentery of cattle

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CHRONIC BACTERIAL DYSENTERY OF CATTLE.®

By John R. Mohler, V. M. D.,

Chief of the Pathological Division.

Chronic bacterial dysentery is a chronic infectious disease of bo-
vines caused by an acid-fast bacillus simulating the tubercle bacillus.
It is characterized by marked diarrhea, anemia, and emaciation, ter-
minating in death. It has also been termed by various European
investigators Johne’s disease, chronic bacterial enteritis, chronic hy-
pertrophic enteritis, and chronic bovine pseudo-tuberculosis enteritis.

Recently this disease has been observed in the United States for the
first time by Pearson in Pennsylvania cattle, and later by Beebe in
Minnesota and by Mohler in Virginia cattle and in an imported heifer
from the Island of Jersey at the Athenia, N. J., quarantine station
of the Bureau of Animal Industry. Pearson has proposed the name
“ chronic bacterial dysentery ” for this affection.

The disease was first studied in 1895 by Johne and Frothingham
in Dresden, but they were inclined to attribute the cause of the pecu-
liar lesions of enteritis which they observed to the avian tubercle
bacillus. In 1904 Markus reported the disease in Holland, and sub-
sequently it was observed in Belgium, Switzerland, Denmark, and
Great Britain.

CAUSE.

The bacillus which has been invariably demonstrated in the intes-
tinal lesions and mesenteric lymph glands in this disease is a rod
about 2 to 3 microns long and 0.5 micron wide. It stains more or less
irregularly, like the tubercle bacillus, and, moreover, the similarity
goes farther in that the organism is also strongly acid-fast, which
facts led Johne and Frothingham to surmise that the disease was
caused by avian tubercle bacilli. Plowever, it has now been plainly
demonstrated that the bacillus of chronic bacterial dysentery is
readily distinguished from those organisms, for while it resembles
the tubercle bacillus in form and staining qualities, no one has suc-

° Reprinted from the Twenty-fifth Annual Report of the Bureau of Animal
Industry (1908).

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2

ceeded in growing it in culture media or in reproducing the disease by
injecting experiment animals.

SYMPTOMS.

Probably the first symptom noticed is that the animal is losing con-
dition despite the fact that its appetite is good and the feed nourish-
ing. This is soon followed by a diarrhea which is moderate at first,
but soon becomes excessive and may be either irregular or persistent,
the feces being of the consistency of molasses and passed frequently.
In the meantime the hair becomes dry and harsh and the animal falls
off considerably in weight. (See fig. 1.) The temperature, how-
ever, remains about normal. The appetite does not seem to be greatly

impaired until the
last few weeks of
life, but neverthe-
less emaciation
continues, the ani-
mal becomes more
and more anemic,
great muscular
weakness and ex-
haustion are mani-
fested, and death
follows, appar-
ently as the result
of the persistent
diarrhea and great
emaciation. The
disease may con-
tinue for four or
five weeks or may last for a year or even longer before death intervenes.

LESIONS.

The lesions observed on post-mortem are remarkably slight and out
of all proportion to the severity of the symptoms manifested. The
disease appears to start in the small intestines, especially in the lower
portion, where the lesions are usually the most marked, but it also
involves the large intestines, including the rectum. The mucous
membrane may alone be affected, although usually in the long-stand-
ing cases the submucosa is also invaded, and the entire intestinal wall
is then much thicker than normal and the tissue infiltrated with an
inflammatory exudate. The mucous membrane or inside lining mem-
brane is markedly wrinkled or corrugated, showing large coarse folds
with more or less reddening or hemorrhagic patches or spots on the
summits of the ridges, especially noticeable in the large intestines.

[Cir. 156]

3

The mesenteric lymph glands are usually somewhat enlarged and ap-
pear watery on section. The other organs do not appear to be
affected except from the anemia present in the later stages of the
disease.

DIFFERENTIAL DIAGNOSIS.

The principal disease with which bacterial dysentery may be
confused is tuberculosis, but the application of the tuberculin test
will readily diagnose the latter disease, while no reaction will be
noted in case the injected animal is suffering with only the former
affection. The disease may also be mistaken for the parasitic affec-
tions resulting from stomach worms (verminous gastritis) and
intestinal parasites, especially uncinariasis, in which case a micro-
scopic examination of the feces is necessary in order to establish
definitely the diagnosis.

TREATMENT.

As with all other forms of infectious disease, it is advisable to
separate immediately the diseased and suspected cattle from the
healthy animals. The feces passed by the former should be placed
on cultivated soil where healthy cattle would not be exposed to them,
as the bacilli producing the disease are readily found in such manure.
The stalls, stables, and barnyards should also be thoroughly disin-
fected, special attention being given to those places which have been
soiled by feces.

The administration of medicines has thus far been quite unsatis-
factory, although treatment should be directed toward disinfecting
the intestines with intestinal antiseptics, such as creolin in 2-tea-
spoonful doses given twice daily. Salol, turpentine, or subnitrate of
bismuth in a starch or wheat-flour gruel may also give temporary
relief, but the diarrhea is likely to reappear and cause the death of
the animal. In all cases the food must be carefully selected to assure
good quality, and should consist preferably of nutritious dry feed.

[Cir. 156]

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