106
'Wah'
of Goats and Sheep in Sind
the primary local lesion is generally in the udder,
which becomes hot, swollen and painful, while
the milk becomes either thick or thin and watery,
occasionally blood-tinged with fibrin clots and
is greatly reduced in quantity. A painful swelling
of the knee and hock joints appears three or four
days after the udder complications, giving rise to
acute lameness. The swelling of the udder
subsides within seven to ten days and is followed
by an atrophy of the gland. The milk secretion
does not return to normal. The few drops which
can be squeezed out with great difficulty are
greatly altered in consistency and appearance,
having become either thick or watery and
flocculent. In about three months the swelling
of the joints decreases and the lameness dis-
appears ; the mammary gland becomes soft and
on palpation may be found to contain indurated
areas. Usually only one quarter of the udder is
involved. When the whole udder is involved,
there is no secretion of milk in the affected
quarters on the next kidding, with the result that
the young ones die of starvation. Lambs and
kids may be infected in utero and show swelling
of the hock, knee or fetlock joints at birth and are
unable to stand (Plate XI). The majority
of them die after a few days.
Sometimes the disease affects the mammary
glands only. In one outbreak 5 per cent of the
affected goats and sheep had inflammatory eye
lesions, viz., conjunctivitis, corneal opacity and
the presence of highly-injected minute blood
vessels in the sclera, immediately around the
cornea. In this particular outbreak 20 per cent
of the animals showed obvious lachrymation. The
lactating animals are the most susceptible, but
males and the non-lactating animals may also be
affected. Young animals are less susceptible
than adults.
It has been observed that abortion is quite
common among goats suffering from Wah, the
percentage of abortion varying from 5 to 20 per
cent.
It may be mentioned here that generally the
disease is seen in goats only, while sheep in the
same area, though grazing and living with affected
goats, seem to remain free. Only one outbreak
has been recorded in which both goats and sheep
were seen to be affected. In the experimental
animals the symptoms observed were the same as
those noticed in natural cases. Under natural
and experimental conditions only a certain per-
centage of animals contract the disease.
MORBID ANATOMY
Autopsy on ten. natural cases of the disease and
three experimental goats revealed that the main
changes were confined to the knee and mammary
glands. The postmortem findings are summarized
below in detail :
Knee joints. The swollen joints were painful-
and soft on pressure, and contained an excess of
fluid. The bursae were thickened and there was
fibrositis.
Mammary gland. The gland was atrophied and
soft and had indurated areas. In acute cases the
gland was inflammed and showed areas of necrosis,
The mammary lymphatic glands were also
enlarged in acute cases.
In some cases the liver appeared to be enlarged ;
sometimes there was infestation with liver-flukes,
while at other times no parasite could be found.
Other organs were normal, except that the
stomach and intestines showed a varying degree
of helminthic infestation, among which amphis-
tomes, Haemonchus contortus, and Trichuris ovis
were predominant.
HISTOPATHOLOGY
Knee joints. There was peri-arthritis, with
proliferation of fibrous tissue. In some cases
only bursitis and superficial fibrositis were seen.
Udder. Inflammatory changes with multiple
abscesses were noticed in experimental animals,
which had been given infective material through
the teat canal. These changes were also noticed
in some natural cases. In some cases, advanced
hyperplasia of the fibrous tissue with monocytic
infiltration round the acini was seen, and in others
slight monocytic infiltration round the acini and
very slight fibrosis were noticed.
Liver. Biliary and portal cirrhosis, extensive
haemorrhagic areas (haemorrhagic infarcts) and
verminous nodules, eosinophile infiltration, asso-
ciated with necrotic changes were observed. No
helminth parasites could be detected in sections.
BACTERIOLOGY
Examinations of smears of blood, milk and films
from the cut surface of the mammary gland and
from knee joint fluid repeatedly proved negative
for pathogenic micro-organisms and protozooa.
In most cases the cultural examination of
different organs, viz., liver, spleen, kidney,
mammary gland, knee joint, milk and urine
failed to reveal any pathogenic organisms.
In one case coliform organisms were isolated
from the liver, spleen, kidneys, heart-blood and
knee-joints, but they were of no pathogenic
significance, as both the young and old were seen
to be affected alike and there was nothing to
suggest navel-ill or joint-ill. In one instance
staphylococci were isolated from the joint fluid.
These presumably were contaminants, as no sign
of pus or abscess formation has ever been seen in
the knee joints.
Milk, blood and urine from affected animals
were culturally examined for Brucella abortus