Giardiasis in dairy calves: effects of fenbendazole treatment on intestinal structure and function

Immunopathology of giardiasis: the role of lymphocytes in intestinal epithelial injury and malfunction

“…The use of these models has significantly improved our understanding of the pathobiology of this parasite. Injury to small intestinal microvilli has been reported in mice, Mongolian gerbils, cattle, and goats infected with this parasite , 1992, Kudela et al 1998, O'Handley et al 2001. Together, these observations indicate that in giardiasis, loss of absorptive surface area coupled with defective glucose-stimulated electrolyte, fluid, and solute absorption, rather than hypersecretory processes such as those observed during cholera, are responsible for excessive loss of fluids in the stools.…”

“…First, in immuno-competent but not in T-cell deficient animals, acute giardiasis causes a diffuse loss of epithelial brush border surface area and decreases sucrase and maltase activities (Scott et al 2000). During the acute phase of the infection, epithelial abnormalities were not seen in the jejunum of Gupta et al 1973, Chawla 1975, Ducombe et al 1978, Gillon et al 1982, Faubert 1988, Belosevic et al 1989, 1992, Favennec et al 1991, Katelaris et al 1991, Cevallos et al 1995, Mohammed et al 1995, O'Handley et al 2001 athymic mice, despite comparable parasitic loads to those seen in immuno-competent animals, implying that the lack of microvillous injury could not be attributed to a reduction in trophozoite numbers. Second, experiments using in vivo T lymphocyte transfer into naïve animals demonstrate that brush border injury and malfunction in giardiasis are mediated by CD8 + T lymphocytes, while CD4 + T lymphocytes are responsible for parasite clearance (Scott et al 2004).…”

Effects of yeast based toxin binder supplementation on growth performance and intestinal microarchitecture in male buffalo calves (Bubalus bubalis) exposed to different concentrations of Aflatoxin B1.

“…Impairments in the intestinal mucosa caused by AFB1 decreases its nutrient absorbing ability (Liu et al, 2011). Villus surface area depends upon the dimensions of villus (Hou et al, 2012), and higher growth rates are associated with greater villus Handley et al, 2001), caused by AFB1. Beta-glucans (ß-glucans) are carbohydrates having linked glucose molecules which are major components of yeast cell wall (Volman et al, 2008).…”

Pharmacological Treatment of Giardiasis

“…This description is similar to those given by other authors but in species such as sheep (Ovis orientalis), where at a dose of 10 mg/kg once daily for three days is equally effective that in canines [30]; some authors, in particular Geurden et al, suggest that the standard dose in sheep for G. intestinalis should be 15 mg/kg every 24 h for 3 days [31]. In Bos taurus calves, the dose of fenbendazole is much smaller, where 5 mg/kg every 24 h oral for 3 days is effective in 90% [32].…”