Dry food (8–10% moisture) is generally made by extrusion cooking under high heat and pressure.
Fat may then be sprayed on the food to increase palatability, and other minor ingredients, such as heat-sensitive vitamins, which would be destroyed in the extrusion process, may be added.
Dry food is most often packed in multi-wall paper bags, sometimes with a plastic film layer; similar bag styles with film laminates or coextrusions are also used. (source)
Can guinea pigs eat dried cat food?
They can nibble it, but it holds no nutritional value for guinea pigs and so shouldn’t be a regular part of their diet.
For more foods that guinea pigs can and can’t eat, check out our guinea pig food list