In the previous Halacha, we have explained that a Chametz food which becomes inedible, such as bread which was burnt until it becomes ashes, may be retained in a Jews possession on Pesach. It is likewise permissible to benefit from this Chametz on Pesach. However, this only applies when the food becomes so completely inedible that it is not even edible for a dog, as we have discussed.
A Chametz Mixture which becomes Inedible
A “Chametz mixture” refers to a food which is not actual Chametz (such as bread) but merely has a Chametz ingredient mixed into it (and this food item does not have the ability to leaven other foods), such as cheese which has some flour mixed into it. Chametz mixtures share the same law as actual Chametz in that if one retains Chametz mixtures in his possession on Pesach, he has transgressed the prohibition of “Do not Chametz be seen or found in your possession.”
There is nevertheless a basic, underlying distinction between actual Chametz and Chametz mixtures: Whereas actual Chametz may not be retained in one’s possession on Pesach unless it becomes completely inedible for a dog, a Chametz mixture may be retained in one’s possession as long as it is inedible for human beings (even if it is still edible for a dog).
Maran Ha’Shulchan Aruch (Chapter 442, Section 4) rules likewise: “Regarding a food item which has Chametz mixed into it but is completely inedible for human beings, although it is permissible to retain it in one’s possession, one may not eat it until after Pesach.” The Poskim explain that it is likewise permissible to benefit from this Chametz mixture. The Rambam (Chapter 4 of Hilchot Chametz U’Matzah Halacha 8) and other Poskim that the Bet Yosef quotes (in the beginning of the aforementioned chapter) rule accordingly.
Bird, Dog, and Cat Food
As we have discussed, just as it is forbidden to eat Chametz on Pesach, it is likewise forbidden to benefit from it. It is therefore forbidden to feed animals Chametz food products on Pesach since this would benefit the person feeding them.
Thus, if one raises animals at home and must feed them on Pesach, one must take care not to transgress prohibitions of Chametz and must purchase only Chametz-free food for one’s pets. This is especially true regarding birds, dogs, and cats, for although the food for these pets is not particularly tasty for humans, it is nevertheless not completely inedible and may not be used on Pesach.
Tropical Fish Food
The Halacha is nevertheless different regarding fish. As we have explained, if a food is not actual Chametz and is merely a Chametz mixture, if it inedible for humans, it is permissible to benefit from it on Pesach even if it is still edible for dogs. It will similarly be permissible to feed it to animals.
Since the food for tropical fish is usually quite putrid and is completely inedible for human beings in addition to the fact that it is not made of actual Chametz and merely contains Chametz mixtures which are not even noticeable, although it is still absolutely forbidden for one to eat such fish food on Pesach, one may nevertheless benefit from it and feed it to one’s tropical fish.
Clearly, one should take care that no crumbs of this fish food fall in a place where people may eat from it, for such a Chametz mixture is certainly forbidden for human consumption (one should take care not to eat this food all year round because of other serious Kashrut concerns).
We have written about all of this last year and we had concluded that indeed, Hagaon Harav Ben-Zion Abba Shaul zt”l has ruled that one may feed one’s fish with such food even if contains Chametz mixtures (see Ohr Le’Zion, Volume 3, page 92).
Several years ago, we had shown this ruling of the Ohr Le’Zion to Maran zt”l and he replied that he would delve into the matter and notify us if it would be permissible to follow this ruling practically speaking. A short while later, he indeed notified us that this ruling is in accordance with Halacha and may be followed. We have likewise ruled accordingly for someone who had multiple aquariums and wished to feed the fish in his possession with such fish food containing Chametz mixtures.
The following year, there were those who questioned Maran zt”l about this ruling which we have publicized in his name at which point Maran zt”l explained this law to them at length and proved to them that we were indeed correct.
Kosher for Pesach Medications
Regarding pills and capsules with medication for headaches and the like, although they may contain Chametz mixtures (such as wheat starch and the like),if they are truly putrid and have become inedible for a dog before Pesach and they are swallowed as is, they may be used on Pesach.
Nevertheless, since there is room for stringency regarding such medications, only one who is truly ill (even if it is non-life-threatening) or those who require relaxants and the like should use them. However, if one merely has some minor aches and pains, they should not be used. One should certainly not act leniently regarding vitamins. Nowadays, there are kosher for Pesach vitamins and dietary supplements manufactured and one should use only these during Pesach.
In the United States as well as in Israel, there are various Kashrut organizations which publish lists of kosher for Pesach medications and it is preferable to use only these medications even in a place of illness.