Cobalamin Deficiency

This chapter presents information on etiology/pathophysiology, signalment/history, clinical features, differential diagnosis, diagnostics and therapeutics of cobalamin deficiency in cats and dogs. Animal-derived protein serves as the only natural source of cobalamin in dogs and cats. Thus, dogs and cats that are fed an exclusively vegan diet must receive cobalamin supplementation to avoid cobalamin deficiency. The main causes of cobalamin deficiency in dogs and cats include chronic gastrointestinal disease involving the ileum, exocrine pancreatic insufficiency, short bowel syndrome, and, in rare cases, inherited cobalamin malabsorption or dietary deficiencies. In dogs and cats with short bowel syndrome, cobalamin can no longer be absorbed because the ileum, the main site of cobalamin absorption in dogs and cats, is no longer present. Exocrine pancreatic insufficiency, the most common cause of cobalamin deficiency, is particularly common in German shepherd dogs. Cobalamin supplementation is the treatment of choice in patients with cobalamin deficiency.