NASAL CARRIERS IN BOVINE PASTEURELLOSIS
By NAGIA SINGH, Research Scholar Indian Veterinary Research Institute, Mukteswar (U.P.), India
(Received for publication on 23 December 1947)
T HE older view that in nature Pasteurellosis results from the ingestion of Pasteurella-septica
leading a saprophytic existence in the outer world is no longer tenable. To explain the spread of
the disease transmission by vectors had been postulated. Thus Magnusson [1914] suggested that
some sucking insect was responsible for a large epidemic which occurred among reindeer in Sweden.
Daubney, Hudson and Roberts [1934] adduced some evidence that the disease in cattle could be
carried by the flea, Ctenocephalus-felis-bouche. This was supported by Mehra [1941-1943] who suc-
ceeded in transmitting the disease in rabbits and in large animals through the agency of the same
flea. This matter has been investigated by Sapre [1945] with some thoroughness. Using a highly
virulent strain of Pasteurella he has found that while fleas can transmit the disease with ease in rabbits,
such transmission failed or sometimes occurred only with the greatest difficulty in young water buffaloes
which are highly susceptible in nature. At the present time it is considered with much justification
that in all probability respiratory carriers are responsible for maintaining and spreading pasteure-
llosis in cattle or as it is still termed, haemorrhagic septicaemia. The same is true of swine [Uhlenhuth
and Haendel 1913]. In the case of rabbits, Dekruif [1921, 1922a, b, 1923] observed Pasteurella orga-
nisms in the nose of a large proportion of apparently normal animals living in association with rabbits
suffering from snuffles. Webster [1924a, b] found that preceding an outbreak of rabbits Pasteurallosis
there was a rise in the normal carrier rate and that the susceptibility of rabbits varried greatly, some
being highly resistant, others succumbing with ease. With fowls, Pritchett, Beaudette and Hughes
[1930], showed that 11 per cent of healthy birds acted as carriers and that it was from such birds that
the organisims spread and gave rise during the winter months to the various forms of infections viz.,
carriers, localized upper respiratory disease and typical fowl cholera. Hughes and Pritchett [1930]
showed that Past. septica was incapable of inciting fowl cholera when introduced directly into the
alimentary tract, but could produce the typical disease when administered into the upper respiratory
passages. Jorgenson [1925] found that in cattle a considerable proportion of normal animals (about
15 per cent) carried Past. septica in the upper respiratory tract. All such observations suggest that
natural infection occurs through the nose and is dependant on the presence of carriers.
The present work was undertaken in order to ascertain the proportion of Pasteurella carriers
in selected groups of cattle and buffaloes. In all, the nasal passages of 300 animals were swabbed,
viz., 100 slaughtered animals at the abattoir and 200 live animals in areas in the United Provinces
where Pasteurellosis prevails. The animals examined were mainly young buffaloes. Of the dead
animals, 7 per cent were found to be pasteurella carriers while the carrier percentages among live
animals were:
Area
1
2
3
No.
examined
60
60
80
Carriers
per cent
5.0
3.3
3.75
EXPERIMENTAL
The swabs were made of copper wire 46 cms. long with a cotton wool binding at one end. This
was placed within a shorter rubber tube of 0.6 to 1.0 cm. internal diameter, so that the wool binding
lay near one end. Both ends of the rubber tube were then plugged and the whole outfit sterilized.
For swabbing the nasal chamber, wet swabs soaked either in sterile normal saline or in sterile broth
77
C