Chametz Mixtures and Pet Food – A Bold and Controversial Approach by Rabbi Chaim Jachter



All major Kashrut organizations in the United States, including the Orthodox Union, Star-K and the Chicago Rabbinical Council, post instructions on their websites for pet owners to only keep Chametz free pet food in their homes during Pesach. Common practice throughout the Orthodox community reflects these instructions.

There is a potential alternative, however, based on the following rulings of Rav Ben Zion Abba Sha’ul and the Israeli military rabbinate. This is of major interest since, as pet owners know well, many animals react severely when their diet is changed. This is not surprising as the Gemara (Ketubot 110b and elsewhere) teaches “Shinui Veset Techilat Choli,” changing one’s routine triggers illness. The difficulty animals experience when their eating routine is changed in reflected in Rashi to Bereishit 7:24 s.v. Ach No’ach, which describes how the lion on No’ach’s Teivah bit him when the lion’s food was served late. Many animals will regurgitate frequently and suffer considerably when their food regime is altered.

Chametz Gamur vs. Ta’arovet Chametz

Chametz food which becomes inedible, such as bread which was burnt to ashes, may be retained in a Jew’s possession and used for benefit on Pesach. However, this only applies to food that even a dog wouldn’t eat (Nifsal Mei’Achilat Kelev; Pesachim 21b and Shulchan Aruch Orach Chaim 442:2 and 445:2).

A “Chametz mixture” (Ta’arovet Chametz) 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 “Lo Yeira’eh Lecha Chametz”, do not let Chametz be seen or found in your possession.

There is nevertheless a basic underlying distinction between pure Chametz and Chametz mixtures: Whereas actual Chametz may not be retained in one’s possession on Pesach unless it becomes inedible for a dog, a Chametz mixture may be retained in one’s possession as long as a human being would not eat it (even if a dog would).

The Shulchan Aruch (Orach Chaim 442:4) rules: “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 (Mishnah Berurah 442:22 and Chazon Ish Orach Chaim 116:8). The Rambam (Hilchot Chametz U’Matzah 4:8) and other Rishonim that the Bet Yosef quotes (in the beginning of the aforementioned chapter) rule accordingly.

Tropical Fish Food - Rulings of Chacham Ben Tzion Abba Sha’ul and Hacham Ovadia Yosef

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. The Halacha is nevertheless different regarding fish food, according to two major Sephardic Posekim. Chacham Ben Tzion Abba Sha’ul and Chacham Ovadia Yosef. As we have explained, if a food is not actual Chametz and is merely a Chametz mixture and 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, and it also merely contains unnoticeable Chametz mixtures, one may benefit from it and feed it to one’s tropical fish (although it is still, of course, forbidden for one to eat such fish food on Pesach).

Rav Ben-Zion Abba Shaul has ruled that one may feed one’s fish with such food, even if contains Chametz mixtures (Ohr Le’Zion 3:92). Rav Ovadia Yosef’s grandson, Rav Yaakov Sasson writes the following on his Halacha Yomit website:

“Several years ago, we had shown this ruling of the Ohr Le’Zion to Maran zt”l (Rav Ovadia Yosef) 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.”

Dog, Cat and Bird Food

Rav Sasson, however, believes that this lenient approach does not apply to dog food. He writes:

“If one raises animals at home and must feed them on Pesach, one must take care to not 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”.

Rav Sasson does not regard dog, cat and bird food to be Nifsal Mei’Achilat Adam. Indeed, Rav Shlomo Zalman Auerbach writes (Teshuvot Minchat Shlomo 1:17) in a landmark Teshuvah regarding taking medicine that contains Chametz on Pesach writes “There are many medications that even if they are somewhat bitter, it is possible nevertheless that it is not classified as “Eino Ra’ui Le’Achilat Adam” simply because we are “Mefunakim” (fussy)”. Rav Shlomo Zalman cites as evidence the Rambam’s ruling (Hilchot Tumat Ochalin 10:2) that urine is not considered Nifsal Mei’Achilat Adam. Rav Shlomo Zalman suggests that the Halacha maintains a low threshold for what is considered edible for a human being, and that this might not change with the perceptions of the people of the times.

Similarly, in 1986 I told Rav Yehuda Amital that Rav Soloveitchik stated that toothpaste was not Ra’ui LeAchilat Kelev. Rav Amital responded that he disagreed as he recalled that in the Russian labor camps during World War Two, people would put toothpaste on their bread to give it some taste. Rav Amital’s response illustrates the difficulty (and subjectivity) involved in assessing what is considered Ra’ui LeAchilat Kelev.

However, Rav Yosef Adler told me that Rav Soloveitchik did not adopt Rav Amital’s approach. The Rav did not believe that we gauge the standards of Ra’ui LeAchilat Adam or Kelev based on extreme circumstances or based on the standards of pre-modern times. In much of the Orthodox community this ruling is followed and regular toothpaste is used on Pesach.

The Rav’s approach seems to be supported by a straightforward reading of the Shulchan Aruch (Orach Chaim 442:4 and 442:10) as well as the Mishnah Berurah (442:45). The Shulchan Aruch writes that that which is not “Ma’achal Kol Bnei Adam,” food that everyone would eat, is permitted to be retained in one’s home during Pesach. Likewise, the Shulchan Aruch permits using ink made from barley on Pesach. The Mishnah Berurah adds that this is permitted even though scribes sometimes place the ink in their mouths!

A Ruling from the Israeli Military Rabbinate

 An interesting article appears in Techumin volume 35 (pages 47-54) authored by Rav Avihud Schwartz, who serves as the head of Halachic policy for the Israeli Military Rabbinate. In a meticulously and thoroughly researched article, Rav Schwartz discusses protocols regarding the serving food of the very specially trained dogs of Tzahal’s canine corps. These dogs are specially trained and are essential in anti-terrorist missions in discovering explosives and other dangerous devices.

As per the custom in the Orthodox community these animals were at first served non-Chametz food during Pesach. Many of the dogs reacted severely and a significant number had to be taken out of service during Pesach, since the change in food impacted them so severely.

The military veterinarians did not want the animals’ diet changed for Pesach and Tzahal’s Rabbinate had to decide if this was permissible. Rav Schwartz writes that it is permissible to adopt a lenient approach to this matter since the grain content is less than fifty percent. Rav Schwartz regarded the grain content of this food to be not suitable for human consumption. He cites Rav Dov Lior, the Rosh Yeshiva of the Yeshivat Hesder of Kiryat Arba,  who endorsed this ruling as well. Rav Schwartz adds that Piku’ach Nefesh is a consideration since incapacitating such special animals exposes the Israeli public to the infiltrations of terrorists (Rachamana Leitzlan).

 Application to Household Pets

The big question, of course, is whether this ruling may be applied to pets in a civilian home on Pesach. One could put forth the argument that as long as the grain content of the dog food is less than fifty percent, the dog food is regarded as Ta’arovet Chametz that is not suitable for human consumption. On the other hand, one could argue, based on Rav Auerbach and Rav Amital, that dog food is not Nifsal Mei’achilat Adam. In addition, one could argue that a lenient ruling issued in the context of a borderline Piku’ach Nefesh situation should not apply to civilian situations that are not at all Pikuach Nefesh. However, beleaguered pet owners who have experienced their animals’ severe suffering on Pesach will testify as to the pressing need to be lenient, if such leniency is well-founded in Halacha.  


The standard approach in the Orthodox community for decades has been that one should not serve one’s animals pet food that contain Chametz on Pesach. However, an argument could be made permitting serving pet food containing Chametz provided that the grain content of the pet food is less than fifty percent. One should consult his Rabbi for a ruling about this challenging issue. For clarification, although we cited the rulings of Hacham Ben Zion and Hacham Ovadia, there is no difference between Sepharadim and Ashkenazim regarding this issue.

Chametz Mixtures and Pet Food-A Bold and Controversial Approach-Part II by Rabbi Chaim Jachter

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