Meat 用法根據 AAFCO 的定義如下：
來自屠宰哺乳動物的乾淨肉，只可以用附連骨骼的橫紋肌，或者舌頭、橫隔膜、心臟、食道的部位。肌肉當中可能包含正常會出現的脂肪、皮膚、肌腱、神經和血管，也可能不包含。這些肉應該適合製作動物食品。
換句話說，肉類主要是動物的肌肉組織，但可能包括脂肪、軟骨和通常附連在肌肉的其他組織，一如我們在街市可以買到供人食用的未熟肉類一樣。這可能包括外表不那麼令人垂涎三尺的肉塊，亦可能包括心臟肌肉以及將心肺與其他內臟分隔的肌肉。但總而言之，這些都是肌肉組織。
用以製作貓狗糧的肉類，通常是以機器拆開骨肉。但要注意的是，骨骼並不包括在內。
Meat: the clean flesh derived from slaughtered mammals and limited to that part of the striate muscle which is skeletal or that part which is found in the tongue, in the diaphragm, in the heart or in the esophagus; with or without the accompanying and overlying fat and portions of the skin, sinew, nerve and blood vessels which normally accompany the flesh. It shall be suitable for animal food. If it bears a name descriptive of its kind, it must correspond thereto.
In other words, meat is primarily the muscle tissue of the animal, but may include fat, gristle and other tissues normally accompanying the muscle, similar to what is sometimes seen in raw meat sold for human consumption. This may include the less appealing cuts of meat, including the heart muscle and the muscle that separates the heart and lungs from the rest of the internal organs, but it is still muscle tissue.
However, it does not include bone. Meat for pet food often is “mechanically separated,” meaning machines strip the muscle from the bone. This results in a finely-ground product with a paste-like consistency (similar to what is used in hot dogs).
如果你在貓狗糧的包裝標籤看到 Beef（牛）、 Chicken（雞）、 Duck（鴨）等字眼，代表貓狗糧是用該動物之肌肉群製成的。
