ABSTRACTS
339
Causes of deaths among calves in dairy herds. R. LOVELL (1939).
Vet. Record 51, 1081
I N this article the common causes of calf mortality have been reviewed. Colibacillosis
salmonellosis, corynebacterium pyogenes infection, pneumonia due to haemolytic
cocco-bacillus, pasteurellosis, helminthiasis, calf-diphtheria, coccidiosis and hydrocyanic
poisoning are dealt with.
Several observations are quoted to support the view that colibacillosis is the result
of the shifting of an equilibrium in favour of Bact. coli which are normally present in the
digestive tract. This shift may be governed by a combination of factors such as defects
in the digestive tract, a delay in feeding leading to over distention and the formation of
undigested coagulable protein in the stomach, the withholding of colostrum or the pre-
sence of a particularly virulent strain of Bact. coli. As the strains of Bact. coli vary
from herd to herd, it appears useless to consider any form of mass immunization. The
other way to avert the disease, is to avoid the predisposing causes by paying attention
to the improved methods of calf rearing.
Salmonella infection in calves is largely due to S. enteritidis var. dublin. Affected
calves suffer from offensive diarrhoea, and may contract pneumonia or septicaemia.
The disease is of some importance in relation to public health, as the organism has been
known to cause food poisoning in man. Another Salmonella sometimes associated with
calf diseases is S. typhimurium.
G. pyogenes infection is regarded as endogenous in its development. Attacked
calves suffer from pleurisy and suppurative pneumonia. It is suggested that the control
of this disease may be attempted by immunization with toxoid.
The infections due to haemolytic cocco-bacilli usually follow the introduction into
the herd of a carrier and calves become predisposed to this infection while in transport
through rail or road. The weather also has its influence, as more cases of infection occur
during the winter months. When attacked, calves suffer from pneumonia or rhinitis.
It is admitted that occasional cases of pneumonia may be due to invasion by true Pasteurel-
la septica.
Several helminthic parasites causing disease in calves are mentioned.. Trichostrongy-
lus sp. is one. Ostertagia ostertagi causes anaemia, general weakness and death, under-
fed and young animals being particularly susceptible. Cooperia oncophora infection
causes a marked anaemia and is often acquired on moist pastures. Haemonchus contortus
leads to constipation, diarrhoea, anaemia and death. Dictyocaulus viviparus causes
' Husk ' or ' Hoose ' in affected animals. The characteristic cough and dyspnoea are
observed.
Hydrocyanic acid poisoning acquired by the intake of linseed cake macerated with
warm water, calf diphtheria caused by Fusiformis necrophorus and characterized by
necrotic changes in the mouth and pharynx, and ' winter dysentry ' or ' black scours '
caused by Vibrio jejuni have been mentioned. Coccidosis is also responsible for disease
in calves. [V. R. R.]
On the toxicity of nicotine for sheep and the use of the nicotine-bluestone
drench for worms in ruminants. H. O. MONNIG (1937). Rev.
Med. Trop. Parasit. 3, 3-10
M IXTURES of nicotine and copper sulphate were first used in the United States for the
treatment of tapeworms in lambs. Some years ago, Monnig devised careful
experiments to ascertain the toxicity of nicotine for sheep, and the use of nicotine-blue-
stone drench for worms in cattle and sheep. As a result of these experiments, it was
found that there was a marked difference in the susceptibility of sheep to nicotine, some
sheep showing more susceptibility than others. A dose of 40 per cent nicotine over 1.5
c.c. was not safe in all cases, although some sheep could tolerate 5 c.c. A safe dose of
copper sulphate should not exceed 2 gm. The administration of nicotine sulphate alone
causes toxicity, incoordination, laboured breathing, degeneration of liver and kidney,
haomorrhagic gastro-enteritis and death in some cases. The addition of copper sulphate