ABSTRACTS
Dieases causing encephalitis in cattle. S. H.
McNUTT (1942). Cornell Vet. 32, 127-34
THE author discusses the differential diagnosis of ence-
phalitis-like conditions, e.g. rabies, aujeszky's disease,
malignant catarrhal fever, listerellosis and sporadic
bovine encephalomyelitis.
Except listerellosis which is caused by a bacterium,
the other conditions described are attributable to virus
infections. True encephalitis may be confused with
toxaemic and metabolic affections such as ketosis, milk-
fever, etc. Certain poisonous substances in mouldy
corn or in forage particularly during drought give rise to
toxaemic symptoms associated with degenerative changes
in the brain, which are apt to be mistaken for encephalitis.
Poisoning, however, results in death quicker than ence-
phalitis.
Of the virus diseases, rabies is perhaps the only one
which is at times difficult to identify clinically, but
laboratory methods lead to its easy diagnosis.
Malignant catarrhal fever and aujeszky's disease are
two other highly fatal encephalitis-like diseases of cattle
caused by viruses. A brief description of these two
diseases and methods of diagnosis are given.
Many species of domestic animals are susceptible to
listerellosis, but the disease is not as serious among cattle
as it is among sheep and goats. Histological and bacte-
riological examinations of brain and cord are essential
aids to diagnosis.
The author describes a newly recognized sporadic
disease of cattle causing encephalomyelitis characterized
by perivascular inflammatory reaction and thrombosis
of the smaller vessels of the brain and cord. The causal
agent is probably a virus and is present in the brain,
lymph nodes, liver, spleen, nasal exudates, urine, milk
and exudates of the pleural and peritoneal cavities, but
not in the blood stream. The presence of sero-fibrinous
exudate in pleural or peritoneal cavity or in both is a
diagnostic feature. Details of observation on the disease
are given. [J.A.I.]
The host specificity of sheep and cattle helminths,
with particular reference to the use of cattle in
cleansing sheep pastures. F. H. S. ROBERTS
(1942). Austr. Vet. J. 18, 19-27
As there are a number of helminths common to both
cattle and sheep Hall, Tetley and Monning consider that
grazing together of these animals would exert a baneful
influence on the degree of infestation in sheep. Bray, on
the other hand, maintains that the grazing together of
these animals woud result in a mutual benefit from the
standpoint of parasitic infestation. Bray's hypothesis
postulates that the parasites of cattle and sheep are not
interchangeable and, if we carry it a little further, it
might be expected that by rotating cattle with sheep the
degree of infestation in sheep pastures would be materially
reduced. Roberts tried to verify this hypothesis by
experiments in Queensland
Lambs infested with (1) Hœmonchus contortus, (2)
Trichostrongylus colubriformis, (3) T. axei, (4) Strongy-
loides papillosus, (5) Cooperia curteicei, (6) Trichuris
parvispiculum, (7) Moniezia expansa, (8) Ostertagia cir-
cumcincta, (9) O. trifurcata, (10) Trichostrongylus vitrinus,
(11) T. rugatus, (12) Bunostomum trigonocephalum, (13)
Oesophagostomum columbianum and (14) Dictyocaulus
filaria were introduced on a pasture which was not visited
by cattle or sheep for over a period of three years. On the
pasture thus infected were introduced calves which were
previously determined to be free from helminthic infection.
At the end of the experiment the calves were found to be
infected with only the first seven species of helminths.
Judging from the moderate degree of infestation of
calves with H. contortus, it would appear that these animals
are resistant to infection with this worm of ovine origin.
Moreover, this infection was rapidly eliminated by them.
T. colubriformis established itself in the calves in fairly
large numbers but the infestation did not persist.
T. axei occurred in the calves in very small numbers
and these were gradually eliminated. C. curticei behaved
in the same manner as H. contortus but the infection was
larger and persisted longer. The calves acquired very
rapidly the infection of S. papillatus, but it was discarded
as rapidly. Only two animals were infected with M.
expansa and the infection in them lasted for a very short
period. T. parvispiculum was fairly well established in
cattle.
From the standpoint of using cattle for controlling sheep
helminths it would appear from the foregoing results
that H. contortus and T. culubriformis deserve special
consideration. Cattle could be used with advantage for
cleansing sheep pastures of T. colubriformis, provided
sufficiently long time is allowed. In the case, of H.
contortus such a procedure would not be advisable since
the larvæ of sheep origin, after their passage through
cattle, are capable of infecting sheep. Moreover, sheep
may be easily infected with larvæ of pure cattle strain.
[G.D.B.]
The effect of Beckmann's treatment by sodium
hydroxide on the digestibility and feeding value
of barley straw for horses. G. WILLIAMSON
(1941). J. Agric. Sci. 31, 488
FEEDING and metabolism experiments were conducted
to find out the value of alkali treated barley straw for
horses. For this purpose old barley straw of inferior
quality was soaked in 10 times its weight of a 1.25 per cent
solution of caustic soda for 12 hours, washed until it was
no longer soapy and drained for 3 hours before feeding.
This treatment resulted in an average loss of 14.5 per cent
of the original dry matter while the composition figures
showed decrease in crude protein, ether extract and
nitrogen-free extract to the extent of 30, 15 and 13 per
cent respectively; on the contrary, the figure for crude
fibre increased by 15 per cent.
Three adult male horses were used as experimental
subjects. Initially they differed in bodily condition and
in the extent of entozoal infestation. One of the horses
was unwell during the experiment. The experiment was
divided into three consecutive periods of 28 to 58 days.
During the first and third periods, untreated barley
straw was used, while in the second the treated material
was employed. The concentrate ration which was com-
mon to all the animals and periods consisted of 1 lb.
crushed oats, ½ lb. flaked maize, ½ lb. medium bran and
9 gm. salt. The treated straw was found to be more
palatable than the untreated one. The data of the animal
which was unwell during the experiment was considered
abnormal, hence those of the other two were relied upon.
On this basis, the digestibility coefficients of the nitrogen-
free extractives and the crude fibre and the starch equi-
valent of the dry matter were 33.2, 28.2 and 5.6 res-
pectively for the untreated straw, the corresponding figures
for the prepared straw being 54.1, 63.7 and 23.6. Ex-
cept for the first few ays in period 1, the nitrogen balance
of the animals was always positive. The animals were
healthier in period 2 when the treated straw was fed,
than in periods 1 and 3. The data incidentally showed
that infestation by worms had no app rent effect on
nutrition. [R. M.]
253