Dear Rabbi Simon
We have recently acquired a (female) dog as a family pet. Our vet has advised us to have her neutered, as is common practice with many household pets (particularly dogs). Is there any objection to this in Jewish law?
TY for your Q. The simple answer is yes, there is an objection.
The Torah prohibits neutering an animal. This is derived from the words “you shall not do so in your land” (Lev. 22:24), following the disqualification of neutered animals as an offering in the Temple, which is understood as a reference to all animals (not just sacrifices, and not just kosher animals). The prohibition is ruled by the Shulhan Arukh (Even Ha-Ezer 5:11), though there is debate concerning a female animal as to whether the transgression is biblical or rabbinic (see Rabbi Moshe Feinstein, Iggerot Moshe, EH 4:34).
The Talmud (Sanhedrin 56b) records a dispute concerning whether removal of reproductive organs is forbidden even for non-Jews or not. The classic commentators differ concerning which opinion is accepted in halakhah. Although some later authorities are lenient (see Arukh Hashulhan, EH 5:26), the Beit Shmuel (EH 5:16) rules that this dispute has not been resolved, so that a doubt remains as to whether the prohibition extends to gentiles or not.
Because of this doubt, it is not permitted to instruct a non-Jewish veterinarian to neuter an animal, since this would be a violation of “do not put a stumbling block before the blind” (Lev. 19:14), ie by asking the veterinarian to neuter the animal, one causes him or her to sin. It may be possible to circumvent the matter by selling the animal to a gentile, as suggested by a number of 19th c. authorities (see Res. Shoel U-meishiv 3:1:229; Hatam Sofer, HM 185; Ha-Elef Lecha Shlomo, EH 23)—but this is only suggested as a strained solution in extenuating circumstances, and there is room to doubt whether the convenience of owning pets will be sufficient cause.
Others have proposed neutering an animal by an indirect method, for instance by means of injection. The late Rav Shmuel Wosner, Shevet HaLevi (6:204) notes that this is permitted concerning asking a non-Jew to neuter a female animal (see Rabbi Joseph Ozarowski, “Tubal Ligation and Jewish Law: An Overview,” Journal of Halacha and Contemporary Society VII (Spring 1984), pp. 42-52). I have read that there are newly developed alternatives to castration, which do not involve the removal (direct or indirect) of reproductive organs, and these will of course be preferable. Whether these are effective, however, remains uncertain (from what I understand).
Some contend that spaying a female dog has attendant health benefits. However it is doubtful if this consideration would set aside an explicit halakhic prohibition.
It would seem (albeit we can only speculate on such matters) that this is an example of Torah legislation promoting respect for the natural order of life itself, including the animal kingdom, and limiting our license to exercise dominion over animals.
Ultimately the best solution is to acquire a pet which has already been neutered. I realise this advice comes too late for your household pet at this point, but it may be an idea to bear in mind for the future.
Rabbi Rashi Simon