Abstract:
The faeces of 11 horses were examined for Fasciola spp. eggs. One of them was positive for Fasciola
hepatica, a finding which was confirmed post-mortem. The 10 negative horses were subsequently infested with
either F. hepatica or Fasciola gigantica, each animal receiving orally from 500-9 500 metacercariae. No
clinical signs were observed and no fluke eggs were detected in the faeces, and neither immature nor adult
Fasciola worms were recovered from the horses slaughtered 16-26 weeks post-infestation with F. hepatica and
28-34 weeks post-infestation with F. gigantica, respectively. The results indicate that horses have a high level
of resistance to both South African Fasciola spp. Factors which can probably explain the conflicting reports for
the prevalences of fascioliasis in horses throughout the world and the varying results obtained in experimental
infestations are briefly considered.
