Introduction: Opium abuse has become a major and growing problem in most countries of the world. including Iran. The Central Nervous System (CNS) is the most affected system by opium. although the cardiovascular and respiratory systems can be affected too. https://echobookmarks.com/story19493449/comparison-of-circulating-metabolite-concentrations-in-dogs-and-cats-when-allowed-to-freely-choose-macronutrient-intake