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57
Milks producing Tuberculous Lesions.
Four specimens produced tuberculosis ; the nature of the condition has in each case been
confirmed by demonstrating tubercle bacilli in the lesions, and is being confirmed by cultivation
in three cases and by histological section of the spleen in one animal, in which the primary
lesion also contained pyogenic cocci.
Milk No. 3.—Dirt—small trace.
Guinea-pig.—Caseous abscess at site of inoculation: typical early lesions in spleen and liver.
Milk No. 23.—Dirt—small trace.
Guinea-pig.—Local and visceral tuberculosis, as in the above.
Milk No. 25.—Dirt—trace.
Guinea-pig.—Local and visceral tuberculosis, as in the above.
Milk No. 38.—Dirt—small trace.
Guinea-pig.—Very large abscess at site of inoculation, containing both pyogenic cocci
and tubercle bacilli. Tuberculous lesions in spleen and liver.
Other Results.
Milk No. 18.—Dirt—small trace.
Guinea-pig.—Died of intercurrent disease twelve days after inoculation. In the material
remaining at the site of inoculation no tubercle bacilli were demonstrable : this result, however,
is inconclusive.
Milk No. 19.—Dirt—large trace.
Guinea-pig.—Large pyogenic abscess at site of inoculation. No tubercle bacilli found
in pus : no lesions elsewhere.
Milk No. 27.—Dirt—small trace.
Guinea-pig.—Pyogenic abscess at site of inoculation. No tubercle bacilli found in pus :
no lesions elsewhere.
To summarise these results : Four milks (3, 23, 25, 38), or 9-5 per cent., contain tubercle
bacilli ; none of these were classifiable as dirty. Of the remainder, five (2, 16, 19, 33 and 40)
were dirty, two (19, 27) contained virulent pyogenic bacteria, but no tubercle bacilli. In one
case (18) the result as to tuberculosis is inconclusive.
These results, considering the small number of samples, are not of great statistical import,
but the investigation is satisfactory, inasmuch as it has resulted in the tracing of definite
cases of infection in three of the herds from which milk was being sent to the City.
The details in connection with four cases in which the tubercle bacillus was present were
forwarded to the appropriate Medical Officers of Health, and the following are extracts
from reports which have been received indicating the conditions at the farms of origin :—
Sample No. 3.
While inspecting the herd by orders of the County Medical Officer, as tubercle bacilli had been
found in the milk produced on this farm, I found two cows in milk that had definite lesions in the udder.
These animals (Nos. 1 and 2) I took under the Order. These animals were in milk when the sample
was taken.
All the other animals were in good condition and showed no symptoms of the disease within the
meaning of the Order. I took two samples of milk from two other cows that had slight induration of
the udder and sent them to the County Laboratories, Ipswich, for testing, but I do not consider they
were in any way tubercular, but did so to make certain.
A red-and-white Ayrshire cow and a red-and-white shorthorn cow were slaughtered on the 21st
instant. The post-mortem examinations revealed that the Ayrshire cow was suffering from Tuberculosis
of the Udder in an advanced stage, and that the shorthorn cow was suffering from Tuberculosis of the
Udder, the disease not being in an advanced stage.
A later report on the result of the samples of milk taken from the two cows which
had a light induration of the udder states that tubercle bacilli were not found.
Sample No. 23.
One cow (No. 3, a black-and-white shorthorn) showed Nodular Induration of the Udder ; a special
sample of milk was taken from this cow for examination and, in addition, the animal is being subjected
to the tuberculin test. No other cow in the herd was singled out for a special sample or for investigation
by the Veterinary Surgeon.
The herd was divided into four groups, and four mixed milk samples were taken ; these will be
subjected to biological examination, and I will let you have further information when the results are
at hand.
A later report received indicates that mixed sample, No. 4, contained the tubercle bacilli,
and I am now waiting to hear the action taken by the Local Authority.
Sample No. 25.
Samples were taken and submitted for microscopical and biological examination. The result
of these examinations has now come to hand and indicate that none of the samples contained tubercle
bacilli.
Sample No. 38.
One sample gave a positive result, and the animal was slaughtered under the Tuberculosis Order
on Thursday, the 19th instant. The mesenteric glands were enlarged for almost the whole length of
the mesentery, varying from 1 inch diameter to the size of a cricket ball in places, and on examination
showed evidence of tuberculosis. The lungs were also affected, as were many of the glands which were
inspected. The udder showed microscopic evidence of tuberculosis, as did the mammary lymphatic
glands.
The details in connection with the five samples reported as dirty, and the two containing
virulent pyogenic bacteria, were forwarded to the appropriate authority for such action as
they thought necessary.