The reasons behind coprophagia fall into 3 categories: Health, nutrition, and behavioral.
1. Health.
There are several illnesses that have coprophagia as one of the symptoms; however, for most of these conditions, there will be other, much more pronounced symptoms. That said, it's always wise to have the following ruled out, if any of these are suspected. Health conditions in which coprophagia may be present include by are not limited to:
- Inflammatory bowel disease. Symptoms include diarrhea, vomiting, weight loss, gas, and/or abdominal pain.
- Intestinal tumors or cancer. Symptoms include diarrhea, vomiting of blood or feces, abdominal swelling, black or tarry stools, and/or hypoglycemia (low blood sugar) which causes confusion, trouble walking, and/or weakness.
- Intestinal bacterial overgrowth. Symptoms include larger or more frequent stools in comparison to food intake, vomiting, gas, weight loss, abdominal pain, and/or increased appetite.
- Parasitic infection (includes worms and some fungal infections). Signs of worms are very varied depending on the type, but include vomiting, diarrhea, coughing, low energy, swollen abdomen, changes in appetite (increase or decrease), weight loss, poor coat texture, skin irritations, and worms that can sometimes be seen in the dog’s stools.
- Lymphangiectasia (intestinal tract disease). Symptoms include weight loss, diarrhea, abdominal pain, swelling in the limbs, vomiting, and/or cough.
- Age-related (young or old) nutrient absorption issues. Even without any health issues at play, very young puppies or older senior adult dogs may simply have troubles absorbing nutrients.
2. Nutritional.
This revolves around fillers, which are ‘empty’ ingredients meant to bulk up dog food (commonly employed as a cost-saving tactic by the manufacturers of cheap, inferior dog foods). Fillers include corn, corn bran, soy, wheats, hulls, husks, some ‘meals’, by-products, certain oats, mill runs, and more.
If a dog eats 1 cup of superior wholesome food, he’ll receive the benefits (fuel and nutrients) of 1 cup of food.
If a dog eats 1 cup of inferior food with fillers, he’ll be full at first (he technically ingested 1 cup of food), and he’ll be receiving some fuel and nutrients, but also a lot of ingredients that the body cannot process. A good portion of fillers will pass through the body, providing nothing.
So, that 1 cup was actually only 3/4 cup or less. Though appearing to eat enough, a dog can be severely lacking in carbs, healthy fats, protein, and a wide range of vitamins and minerals. If this applies to your Beagle, this can cause your dog to seek out another food source. And, a dog’s own feces can be a tempting food source; if the food contained fillers, much of those were not even digested by the body; there are food bits (albeit, low-value ones) mixed within the feces.
In addition, there is a theory that a vitamin-B deficiency may lead to coprophagia, though other vitamins or minerals are suspected as well.