Why would a puppy eat its own poop?

why would a 3 month old puppy eat its own poop if it is getting feed regularly?

im think it has to do with them being hungry

Although it's eating its own poop, and not cat poop, the answers here:
http://www.ehelp.com/questions/10433944/my-dog-keeps-eating-cat-poop
still apply to this question.

okay well its just like when a mom cat eats the pouch when the kittens are born...but you shouldnt let the puppy eat its own poop becuz he would crave for more and start the biting process and try to practically eat you....yell at to stop constently..then he will soon realize to stop but to make this work faster you must take a water bottle (spray bottle) and squirt at him....

that is so true.... you have to spray water on the dog so it will quit and you might have to yell at him alot.... but dont feel bad this is the only way to make him stop

its made a mess and it doesnt want to get into trouble OR... it wasnt digested properly. my dog used to drink her own... nevermind.

This may be a sign your puppy isn't processing or getting enough nutrition. Consult with your vet to rule out this possibility before considering the following:

Is this an indoor or outdoor situation? Dogs by instinct will prefer not to poop where they eat or sleep. Maybe your puppy is trying to clean it's environment. ? If it's an indoor situation then it may clear up when you house break your puppy. The poop will be outside the dog will be inside and therefor the dog cannot eat it's own excrement. You can also aid in this process by Learning how long it takes between when the puppy eats and when it has to poop. Make sure that you take the puppy out during this window of opportunity.