Mortality in pigs inoculated with rotaviruses may be
associated with several interrelated factors that contribute
to more severe diarrhea, for example, low environmental
temperature (Steel and Torres-Medina 1984),
malnutrition (Zijlstra et al. 1997, 1999), and high virus
exposure dose (Shaw et al. 1989). Diarrhea causes dehydration
and electrolyte imbalances, requiring treatment
with oral electrolytes. Malnutrition increases the
severity and duration of rotavirus diarrhea by hampering
the regeneration of damaged intestinal villi, hence
delaying the restoration of enzymatic and absorptive
capacity (Zijlstra et al. 1997). Malabsorption results in
malnutrition and may lead to energy deficiency and
hypothermia. The higher mortality in neonatal pigs is
likely related to more severe and extensive villous
atrophy, combined with decreased extracellular fluid
and energy reserves, compared to slightly older pigs.