seems to be an option

ABSTRACT
Pet food products have been evolving in a variety of directions, but starch ingredients still make up the vast majority of those used. Despite the animal not requiring starch as an essential nutrient. These starches are composed of amylose and amylopectin in various ratios and are tightly held in starch granules.

It is unlocking these granules through cooking that provides the multitude of functions to starch in pet food such as expansion, structure development, and textureplus an increase in overall nutrient and energy utilization to the extreme.

https://www.k-state.edu/pet-food/events/docs/2020/Starches i...

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Note added at 19 hrs (2023-05-22 16:46:42 GMT)
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Another interesting one (co.uk):

For use in dog food the raw grains (and other products containing starch such as roots and tubers) must therefore be “pre-digested”, in other words: the starch must be “broken open” so that the carbohydrates are accessible for further digestion in the intestine of the dog. Even for people, whose intestines are seven times as long in relative terms, roots, raw grain and tubers (for example potatoes), are impossible or difficult to digest and cause the formation of gas, intestinal cramp, and watery faeces. This “breaking open”, or “unlocking”, of the starch happens if the product is heated (cooked) for a certain period of time. Because this unlocking, above all during extrusion (crunchy pellets that remain floating on water), is insufficient, due to the length of heating time being too short, problems with digestion arise, with intestinal complaints as a consequence.

Because of these problems people have the tendency to regard all food containing grain as equally bad. However when the grain (rice, maize, wheat and sorghum) is properly unlocked, these are valuable sources of essential nutrients. Another reason why people talk negatively about grain is the instance of gluten allergy. Gluten allergy (Coeliac disease) can only be caused by grains containing the substance gliadin, for example wheat, but occurs less amongst dogs than is popularly believed. Often the intestinal problems described above are the result of incompletely unlocking the grain, and are interpreted as “gluten allergy”. Maize, rice and sorghum contain no gliadin.

https://www.farmfood.co.uk/knowledge/carbohydrates-in-dog-fo...