Following a general introduction, the extensive
literature on fascioliasis is reviewed. The
distribution, importance, pathogenesis and pathology of
the disease are considered, with special emphasis on
Fasciola gigantica infections.
Field studies are reported on the epidemiology and
control of F. ßiganti.ca in East Africa and a survey
described of infections with Fasciola spp. in African
wild mammals. This survey was undertaken in order to
assess the importance of wild mammals in the
epidemiology of this disease, in view of the increasing
development of game parks and ranching schemes.
The techniques used in the experimental studies are
outlined with emphasis on those modified during this
work. The techniques described include the cultural
methods by which the infective agents were obtained,
with special reference to the large scale production of
metacercariae of F. gigantica and a detailed discussion
of the problems which had to be overcome before this was
possible. Other techniques described include those
used in haematological examinations, faecal egg counts,
liver function tests, serum enzyme assays and other
The difficulties which had to be overcome to
obtain and maintain experimental cattle and sheep free
of intercurrent diseases in Kenya are discussed.
Observations are described which were made in the
course of several experiments using a total of 35 sheep
and 46 cattle in Edinburgh and in Kenya.
In Edinburgh the experiments comprised studies on
the pathogenesis of acute and chronic fascioliasis
(Fasciola hepatica) in sheep.
In Kenya chronic fascioliasis (F. gigantica) was
studied in sheep with special emphasis on the economic
importance of this condition. It was found that the
infected animals gained weight more slowly than the
uninfected controls and that this arose mainly from
differences in the amount of body fat.
Several experiments were carried out in Kenya on
cattle infected with single doses of 500, 1000 or 2000
metacercariae of F. gigantica or with two doses of 500
metacercariae ten weeks apart. The pathogenesis of the
disease and the parasitological findings in these
animals are described in detail. Other studies
described include observations on long term chronic
fascioliasis in cattle.
The gross pathology of P. giçantica infections in
cattle from 2 -51 weeks after infection is also described.
The main finding from these studies is that
F. gigantica appeared to be less pathogenic for cattle
than reported by earlier workers.
There was no evidence of an "acquired self- cure"
under the conditions of these experiments, which would
support the suggestion that resistance to F. sigantica
infections in cattle may be merely related to the
fibrosity of the liver parenchyma. Further support
was found for this suggestion from the study of the
leucocyte levels and other observations.
Evidence was found that F. gigantica has a
relatively short life in cattle.
The dissertation ends with a discussion of the
results from the experimental infections.