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28 Thirty-Fourth. Aimual Report
perimentally 011 a 1lHlHl)G1‘ of mares. Tl1e project has 1lOt had Wha
time to progress to a point where ally definite co11clusio11s may tam
be drawn. for
Diarrhea in Cattle. During the year there has been oc- ” mm,
_ casion to investigate 311Cl study a 11umber of case·s of infectious fm,]
A bacterial enteritis (Johne’s disease) of cattle. The disease has
been positively diagnosed i11 three herds and the diagnosis
confirmed by post-111orte1n and bacteriological findings Hlltl the ieliu
causative factor demonstrated in every ease upon wl1icl1 a post- I€1S’
p mortem has been held. Several attempts have been made to ,
i cultivate the organism, but to date no positive evidence of cul- gil`?
E tural growth can be reported. Some of the inoculated tubes 6613:
l show indication of a very slight growth. Every effort is being dim;
t made to cultivate the organism and to produce so—called I
Johnin, which is used as a diagnostic agent i11 the same way as . _ .
tuberculin for the detection of tuberculosis. illqli
At present avian t-ubereulin is being used in an experimcn- ({5%
tal way as a diagnostic agent. lt has been found that ten cubic WMC
centimeters of avian tubereulin injected subcutancously will uSC(
cause a reaction in some eases. Out of forty animals tested in been
one herd, four gave what is considered a positive reaction and
four a suspicious reaction. Of the four positive reactions, one \
animal was killed and found to be suffering with a severe form WSW
of the disease. The reli»ahility of the test will be quite fully amm
demonstrated if all the animals showing a 1·eaction finally OCCU
Q break with the disease. has l
= reast
; Swine Diseases. The work on swine diseases during the 001,11
  past year has been mainly that of differential diagnosis i11 the mate
laboratory and field, investigating the cause of death in a num- Cum
1 ber of herds where poisoning was suspected and continuing adm,
. observations on infectious necrotic enteritis. Sultg
In the investigations as to the cause of dia1·1·l1ea in shoats, ring
eHort·s to control the disease in large herds have resulted i11 meth
most gratifying success. On two farms where this disease has antit
I resulted i11 a loss of from twenty-Eve to fifty per cent of thc able
pigs reaching the small slioat age, the loss has been reduced al- diag;
most completely i11 one ease and in the other to O1lC—fOUl'lll of doses
i