Ask The Rabbi: Putting to Sleep a Dying Pet

My cat is sick and dying, and it is difficult to watch it suffer. May I take it to a veterinarian to have it put to sleep?

Tzar Balei Chayim (Causing pain to an Animal)

One may not cause pain to an animal. The Talmud discusses whether tzar balei chayim (causing pain to animals) is Biblically or Rabbinically forbidden.[1] Most Rishonim follow the view that tzar balei chayim is a Biblical violation.[2] Additionally, most Achronim hold that tzar balei chayim constitutes a biblical violation.[3] 

Tzar baei chayim can be divided roughly into three categories:

1) To beat or cruelly harm an animal.

2) To make an animal do heavy, painful work.

3) To see an animal suffering in pain and leave it to suffer.

Tzar Balei Chayim when there is a Benefit

In Parshas Noach, the Torah states, (Bereishis 9:3) " Every moving thing that lives shall be yours to eat; like the green vegetation, I have given you everything."

The Panim Meiros,[4] rules that to kill an animal for the benefit of the person is obviously permissible.

The Trumas Hadeshen[5] explains that tzar balei chayim does not apply Tbenefit of profit to the person. The whole purpose of animals is to serve a person. Otherwise, how can one put a heavy load on an animal to carry, for that also pains the animal. The Terumas Hadeshen also suggests that the laws of tzar balei chayim are to distance us from sadistic behavior towards creatures of Hashem.

The Noda B'Yehuda[6] rules that the sport hunting of wild animals for their fur is forbidden either because of animal cruelty or that it potentially endangers the hunter's life.  However, if the hunter makes his livelihood from hunting, they may act leniently, as animals are ultimately for human benefit. However, endangering one's life to hunt seems difficult to justify.

If Killing is included in Tzar Balei Chayim

The Noda B'Yehuda[7] also holds that the prohibition of tzar balei chayim only applies to causing pain or watching the suffering of the creature; however, when one is justifiably killing it, tzar balei chayim does not apply. The Avodas Gershuni[8] writes that the concept of 'baror lo misah yafeh' (giving it the least painful death)[9] does not apply to animals, pests, and bugs, rather only to misos beis din (execution of the beis din).

Killing Cumbersome Flies, Mosquitoes, and Pests

Radbaz[10] writes that a person may kill flies and mosquitoes that are bothering him, for this is considered 'for the needs of the person,' and the needs of a person come first. One need not chase them away, as they will come back anyway.

The Zohar,[11] however, writes that by way of extra piety one should refrain even from killing a snake. It is known that the Arizal would act exceedingly stringently not to kill even a fly. 

Rav Moshe Feinstein writes that even when one has a justifying reason to kill an insect or pest, it is good when possible, not to kill it directly, so as not to act in cruelty, but instead to set a trap to kill it. Rav Moshe writes that it is good to practice this when it is possible to refrain from exercising achzarious (cruelty).[12] 

Putting a Dying Animal to Sleep

In the case of putting a suffering animal to sleep to end its pain, it would be permissible. As mentioned, by killing an animal for any beneficial reason, we brought views that hold that tzar balei chayim does not apply. The only prohibition would be to kill this animal in an achzarios way, which is avoided by putting the animal to sleep painlessly.

One is not required to sit and spend a significant amount of money attending to the sick animal with expensive medical care to prolong its suffering, as this would be a great financial loss to the person. Any financial benefit to the person would outweigh the requirement to make efforts to prolong the life of the dying animal.[13] (This rule is in stark contrast to a dying person who is suffering, where the Torah does not allow euthanasia - mercy killing, Heaven forbid.)

[1] See Bava Metziah 32a-b. The discussion involves from the verse (Shemos 23:5): "If you see your enemy's donkey lying under its burden would you refrain from helping him? You shall surely help along with him."

[2] Rif, Mordechai, Meiri, Rashba, Rosh, Nimukei Yosef, and Sefer Hachinuch (mitvohs 451 and 550) and other Rishonim.

[3] Rama (Choshen Mishpat 272:9). Levush (Orach Chayim 305:18). Magen Avraham (305:11). Mishna Berurah 305:69. Shulchan Aruch Admur Hazaken (hilchos Ovrei derachim v'tzaar balei chayim 8).

[4] Panim Meiros 1:75.

[5] Terumas Hadeshen (psakim u'ksavim 105).

[6] Noda B'Yehuda (Mehadura Tanina Yoreh Deah 10).

[7] Noda B'Yehuda (ibid).

[8] Avodas Gershuni 13.

[9] See Kesubos 37b " Rav Nachman said that Rabbah bar Avuah said on the verse ' And you shall love your neighbor as yourself', choose for him a more pleasant death [as possible]." The Talmud there explains that when killing the eglah arufa, which is done on the back of the neck, we do not do the same by a person obligated to death penalty by the sword, which is done from the neck, so as not increase unnecessary pain.

[10] Radbaz (2:1,127).

[11] Zohar (vol. 2 page 68).

[12] Igros Moshe (Choshen Mishpat 2: 47).

[13] See Be'er Yachezkal (Yoreh Deah pg. 145) that when there is a loss of money, one does not have to pay to avoid tzar balei chayim.