"WOW....a narrow one-sided observation that is lacking the open-mindedness of discovery that made me fall in love with design.   There is a lot of fluff in ANY product category no matter the design thinking process that brought someone to justify it.  The whole digestion thing is a bit of marketing stretch but by no means should that justify a soapbox bashing for a very useful product when done correctly.   I designed products in the pet industry for 5 years and was always amazed at the quirks and uniqueness of animals.  I assure you that dogs will not all like to drink muddy water from a hole because your farm dogs do.  I have to go now and make a call using my bullroarer because modern phones are useless.  "