Its gross, its disgusting and dogs do it? Why? Dr. Mustache explains the science behind this foul habit.br Subscribe to The Pet Collective: Facebook: Twitter: Pinterest: Google+: gplus.tothepetcollectivebr br Coprophagia is common in 50 of dogs. But why? Well it has something to do with biology, behavior and evolution. br br Matt Johnson - Dr. Mustachebr Kate Reynolds - ProducerEditorbr Matt Pagourgis - Producerbr br Atomic © Fontalicious - Derivative Versions © Font Bros. www.fontbros.