Chapter 6. Animal Food on Pesach

In simple terms, since it has been ruled as halachah1  that food which has become unfit for human consumption but is fit for a dog to eat is subject to the obligation of removal, it would follow that animal food containing chametz must be removed, since it is fit for a dog to eat [and it seems that their mention of a dog is not meant specifically, but the same applies to all animals]. However, the reason chametz that has become unfit for human consumption but is fit for a dog to eat must be removed is that it is fit to use for leavening other doughs, in accordance with the opinion of the Rambam2  that chametz which has become unfit for human consumption, if it is fit to leaven other doughs, is included in the category of se’or. But if it is not fit to leaven other doughs, then since it is not fit for human consumption, the prohibition of chametz does not apply to it at all. Therefore, if the animal food contains a chametz mixture in such a way that the form of the chametz has changed, so that, being crushed and mixed with other substances, it is not fit to leaven other doughs3, there is no obligation to remove it, and it is permitted to keep it and use it. However, if the chametz mixed into the animal food is not crushed, such as wheat or barley kernels, then even if it is not fit for human consumption, since it is fit for animal consumption [a dog] and for leavening other doughs, it must be removed. One may give animals alternative food on Pesach that is not chametz, such as millet for parrots, worms for fish, and chicken meat or the like for cats and dogs.