Insights from the Institute: Pet Neutering

Q: May one ask a vet to spay a pet?

A: I frequently get asked this question. People who have pets often prefer to have them neutered, as this makes the animals more docile. However, there are serious halachic issues associated with this. Poskim differentiate between whether a male or female animal is being neutered. The neutering of a male animal is known as castration, whereas neutering a female animal is called spaying.

The Torah (Vayikra 22:24) states that castrating men and male animals is forbidden. This prohibition is known as sirus.1 It is also forbidden to remove a woman and female animal’s reproductive organs. The Gr”a is of the opinion that this is a Torah prohibition. The Taz, however, feels that causing a female animal to become infertile is permitted. According to the Taz, the reason it is forbidden to remove a female animal’s reproductive organs is solely due to tzaar baalei chayim (causing an animal pain).2

[Of course, it is medically possible to cause a woman to become infertile without removing any organs, and the Poskim discuss whether and when a woman is allowed to do so. That topic is beyond the scope of this article.3]

The Gemara quotes an opinion that the prohibition against castrating male animals applies to both Jews and non-Jews. According to this view, a non-Jew is not allowed to castrate his own animal.4 The Gemara brings an opposing opinion that a non-Jew is commanded to keep only the sheva mitzvos benei Noach but is permitted to castrate an animal. That opinion agrees, however, that a Jew who owns an animal cannot instruct a non-Jew to castrate it for him.5

The Shulchan Aruch paskens this latter way, and states that it is forbidden to instruct a non-Jew to castrate a Jew’s animal, but it is permitted for a non-Jew to castrate his own animal. The Rema adds that according to this opinion a Jew may sell an animal to a non-Jew even if he knows that the non-Jew will castrate it. The Rema, however, states that others pasken like the first opinion in the Gemara that it is forbidden for a non-Jew to castrate his own animal. The Rema adds that according to this viewpoint it is forbidden to sell an animal to a non-Jew if it is certain that he will castrate it, as doing so would transgress the prohibition of lifnei iver (causing someone else to sin). The Rema concludes that even this opinion would allow the sale to the non-Jew if he will not be castrating the animal himself. This is because the Jewish seller does not transgress the prohibition of livnei iver if the non-Jewish buyer employs a third party to perform the castration.6

Thus, there is a machlokes as to whether a non-Jew may castrate a male animal. We can now address the question of spaying female animals. Is a non-Jew allowed to spay a female animal by removing its reproductive organs? According to the first opinion in the Rema that a non-Jew is allowed to castrate a male animal, he would also be permitted to spay a female. According to the second opinion in the Rema that a non-Jew is forbidden to castrate a male animal, it is debatable whether he is also forbidden to spay a female. According to the Gr”a that removing a female’s reproductive organs is a Torah prohibition, it would be forbidden. However, according to the Taz that the concern is that of tzaar baalei chayim, it would be permitted for the non-Jew to do so.

Rabbi Heinemann shlit”a once asked Rav Moshe Feinstein zt”l whether a person is allowed to have a non-Jewish vet spay a Jew’s female animal. Rav Moshe paskened that a Jew should not instruct a vet to spay his animal. However, Rav Moshe said that the Jew could tell the vet that he personally is halachically forbidden to spay his animal and would, therefore, like to transfer ownership of the animal and sell it to the vet. After the vet spays the animal, the Jew may then buy it back. This is halachically permitted because of a sfek sfeika – two areas of doubt. First, it is questionable as to whether a non-Jew is commanded to avoid sirus. Second, it is questionable as to whether the prohibition of sirus applies to a female animal.7

Rabbi Heinemann says that the Jew can imply that he may want to buy back the animal after the procedure is performed, but he should not state so explicitly. The Jew may also give the vet some money before the sale, knowing that the vet will use that money to buy the animal from him. For example, the Jew can give the vet a present of $10 and then have the vet buy the animal for $10. After the spaying, a procedure for which the vet generally charges $100, the Jew may buy back the animal from the vet for $100. Better still is to transfer ownership of the animal to the receptionist or some other non-Jew and have him or her get the vet to spay the animal. This procedure may be used only in order to spay a female animal but may not be used in order to castrate a male animal.8


1. רמב”ם פט”ז מהל’ איסורי ביאה הל’ ב

2. שו”ע אהע”ז סי’ ה סעי’ יא וט”ז שם ס”ק ו וגר”א שם ס”ק כה

3. עי’ בשו”ע שם סעי’ יב שמותר לאשה לשתות כוס של עקרין, ועי’ בח”מ וב”ש וט”ז ופ”ת שם ובשו”ת אג”מ אהע”ז ח”א סי’ יג וסי’ סג וח”ד סי’ לד.

4. סנהדרין דף נו ע”ב ודף נז ע”א

5. ב”מ דף צ ע”א וע”ב

6. שו”ע ורמ”א שם סעי’ יד, ועי’ בב”ש שם ס”ק טז שהוא ספיקא דדינא.

7. שמעתי ממו”ר ר’ היינעמאן שליט”א. והישראל לא יצוה את העכו”ם להדיא לסרס את הבהמה אע”פ שהוא של העכו”ם, ואף שהשו”ע הנ”ל כתב שאסור לומר לעכו”ם לסרס בהמה שלנו ומשמע שלסרס בהמה של עכו”ם מותר, עי’ בתוס’ ב”מ דף צ ע”א ד”ה חסום שלדעת הר”י אסור.

8. שמעתי ממו”ר ר’ היינעמאן שליט”א. ואף שהרמ”א התיר לומר לעכו”ם אחד להגיד לעכו”ם שני אף לגבי סירוס זכרים, מ”מ כאן שהוא דרך הערמה יש להחמיר. ואף שלצורך פרנסה מצינו היתר כה”ג אף בדרך הערמה, מ”מ שלא לצורך פרנסה נראה לו שאין להתיר. ועי’ באוצר הפסוקים אהע”ז סי’ ה ס”ק פה מה שהביא בזה משו”ת שואל ומשיב מהדורא תליתאי ח”א סי’ רכט ושו”ת חתם סופר חו”מ סי’ קפה ושו”ת האלף לך שלמה אהע”ז סי’ כג ושו”ת מהר”ם שיק סי’ יא.