Forty-nine percent of all pet dogs will eat poop at some point in their lives. Poop-eating, also known as coprophagy, is usually not well-accepted with the dog’s human family. Theories abound as to why dogs engage in coprophagy, and curiously, it is rarely observed in feral dogs living apart from humans. Dozens of commercial products exist on the market to stop this behavior in our furry friends, but unfortunately few have been shown to be successful.

Here are five possible reasons why we think your pup eats poop:

What is canine parvovirus (AKA parvo)?

Parvo in dogs is a common, highly contagious disease that’s one of the most severe infections a young puppy can get. Fortunately there is an effective vaccine, but some puppies need to have several boosters of the vaccine before they are fully protected.  For the vaccine to be most effective, puppies need to have it at certain ages, or else maternal antibodies may interfere (a form of passive immunity from the mother that can stop the puppy’s own immune system from reacting appropriately to the vaccine).