[SWHouston]

This is called Coprophagia,
and can be cause by a behavioral issue, or deficiency in the Dog’s diet.

Many Puppies eat their Mother’s poop, which is instinctual, considered completely normal, but Coprophagia can be found to exist with older Dogs as well.

Possible dietary deficiency aspects of coprophagia could be Protein/Carbohydrate ratios, Vitamin “B” deficiencies, a lack of Digestive Enzymes, or because they have intestinal parasites.

Dogs may possibly resort to this activity because of several influences, which include:
Being a subordinate member of “their” pack.
Learned behavior from another Dog,
As a result of Overfeeding (their attempt to recycle) to absorb missed nutrients.
As a result of hunger.
Their attempt at Housekeeping, via a concept of sanitation or fear of punishment.
An attempt to attract their Owners attention (regardless of negative “scolding” response).

Reasons as listed above, frequently are hard to analyze. There are a number of remedies to be found, from ingestion of Pumpkin or an Enzyme, to retraining. The fact remains that those approaches are only addressing the symptoms, and unless you can rule out some physiological issue by testing for vitamin deficiency or parasites, you may be putting your Dog in jeopardy.

Given that there may be a medical reason for this activity and in the best interest of the animal, Take it to the Veterinary, and have test done.

Now...
I just want to mention the levels of jeopardy, which your Dog will encounter.

If it has been eating its own, or, eating that of another Dog which you have control over, then the level of jeopardy is not all that great. “Control” meaning that your animals are able to be confined in an area which no other (strange) animal can access, and the Fecal Material available to it, it of it or the immediate Pack. And, when moving one of more out of that area, that you are able to keep them from contacting another animals Feces, and that means getting close enough to just give it a sniff !
Just don’t let that happen !

If you do, even just the slightest touch of their nose to material, and in some instances, even getting close enough to just sniff, is too close, and contamination can occur. You then allow it to rely completely on the Medical protection via previous inoculations, to combat any infection. Shots are very important, but not totally efficient, and sometimes ineffective. Again, just don’t let that happen !
Hope this helps.

Have a good Day !
S.W.