Stock or broth in pet food is another often-misleading term.
While it may refer to actual stock as you or I would understand it (meat, bones or vegetables simmered in water for an extended period of time possibly with herbs or other aromatics for flavour), 'stock' can and is used by some manufacturers to refer to water. Literally just water!
When listed in conjunction with a meat or vegetable (chicken broth or vegetable stock, for example) the ingredient should have some relation to that ingredient but monitoring and regulation is almost non-existent.
To make things worse, some manufacturers have started bracketing stock and broth ingredients with their meat ingredients, allowing them to make quite misleading claims like 'Chicken 50% (chicken meat 25%, chicken stock 25%)'.
If you are at all unsure about the ingredients of your dog food, it is always best to contact the manufacturer directly.
Find foods containing Stock / broth See the full Ingredient Glossary