Warning: feeding animals hydrophilic fiber sources in dry diets

Feeding animals large quantities of dry hydrophilic fiber sources, such as psyllium husk or guar gum, may lead to intestinal obstruction or to other mechanical effects unrelated to the normal function of these materials in human diets. Such fiber sources should be hydrated prior to feeding, rather than being incorporated into dry diets as is. The water-holding capacity of psyllium hydrophilic mucilloid, for example, is greater than or equal to 40 g/g, compared to 2-3 g/g of wheat bran. Consumption of the psyllium product dry would be much more likely to produce intestinal dehydration than would consumption of dry bran. Because of possible untoward effects of high levels of these materials, it may also be more appropriate to feed such fiber sources in quantities approximating that of their potential human dietary consumption, rather than very high quantities that would be unlikely to be attained in human diets.