The health hazards inherent to meat-based diets for cats and dogs are extensive, and difficult to avoid. Unsurprisingly, a range of diseases have been described in the scientific literature following long-term maintenance on such diets. However, numerous reported cases indicate that nutritionally-sound vegetarian diets can result in a range of health benefits. This presentation by a veterinarian with a special interest in the subject explores the health and nutritional aspects associated with meat-based and vegetarian companion animal diets, and provides advice for transitioning to the latter, and for safeguarding health. Further information is at www.vegepets.info.