Comparative responses of cattle, sheep, and goats to larvae of the emerging trematode, Dicrocoelium dendriticum, and development of a diagnostic tool
Phillips, Natalia D.
University of Lethbridge. Faculty of Arts and Science
Lethbridge, Alta : University of Lethbridge, Dept. of Biological Sciences
Parasitic infections caused by species of gastrointestinal ‘worms’ constrain efficient livestock production through the negative effects they have on individual hosts. Dicrocoelium dendriticum is a host generalist trematode that infects grazing mammals and is an introduced species in Alberta. Reducing the impact of emerging, generalist parasites such as this one requires sensitive and specific diagnosis of individual hosts as well as an understanding of relative host responses to infection. I found high interspecific variation in fluke intensity, fluke recruitment, fecal egg counts, and antibody responses in experimentally infected cattle, sheep, and goats. Fluke intensity was significantly higher in goats (x=257±38) than in sheep (x=132±80) or cattle (x=111±103). Anti-fluke IgG and IgM antibody concentrations were high in sheep sera, but undetectable in cattle sera. A coproantigen ELISA detected D. dendriticum protein in cattle and sheep feces at 9 days post-infection. However, assay sensitivities were poor in sheep (x=45%) and cattle (x=23%).
coproantigens , ELISA , enzyme-linked immunosorbent assay , host generalist parasites , host immune response