I'm sorry that your question wasn't answered in a timely manner. Eating dirt is considered a form of pica - the ingestion of nondigestibles which can be caused by gastrointestinal disorders, dental
and oral disease, encephalopathies such as brain tumors
or inflammations, electrolyte imbalances, metabolic diseases, and toxins such as lead. Picas may also be caused by excessive restriction of calories (i.e. weight loss diets) and any medical condition that could cause polyphagia (increased hunger). Similarly, numerous medical conditions from Cushing's disease to diabetes
insipidus might induce polydipsia (increased thirst). Licking
, chewing, polyphagia, polydipsia, and picas can also be a side effect of drug therapy. In geriatric pets, repetitive behaviors
including licking, chewing, and picas might be associated with brain aging and cognitive dysfunction. It would be prudent to have Coco's vet perform a thorough physical exam including diagnostics in the form of blood and urine tests. A gastrointestinal diagnostic panel including a TLI blood test (looking for an exocrine pancreatic insufficiency/lack of digestive enzymes produced by the pancreas) and serum folate and vitamin B12 levels (looking for a malabsorption disorder) is likely to be most cost-effective for you. Please respond with further questions or concerns if you wish.