As surprising as it sounds, I permitted a service dog to enter the sanctuary of Congregation Shaarei Orah, the Sephardic Congregation of Teaneck, this past June. Among the overflow crowd attending the joyous bar mitzvah of Ezzy Douek was a woman who required the company of a service dog.
Rav Soloveitchik--The House Standard
Ample Halachic evidence supports permitting a guide dog or service dog to enter a Beit Kenesset. When I was a student at Yeshivat Har Etzion in 1983, a dog wandered into Rav Lichtenstein’s Shiur room, which prompted my great Rebbe zt”l to relate how a synagogue in Boston refused a blind individual entry with his guide dog. The man subsequently sued the synagogue, and the judge presiding over the case called Rav Yosef Dov Soloveitchik, asking for the stance of Jewish law regarding a guide dog accompanying a blind individual into the Beit Kenesset. Rav Lichtenstein recounted that Rav Soloveitchik replied that it is permissible based on a passage recorded in Berachot 63a. The Talmud there states that just as one would not permit the use of his house as a shortcut, so too one is forbidden to use the synagogue as a shortcut. However, just as one would allow a guest to enter his home and not require him to remove his shoes, so too one is not required to remove his shoes when he enters a synagogue. Similarly, argued Rav Soloveitchik, just as one would certainly permit a blind person to enter his home with his seeing-eye dog, so too a blind person is permitted to enter the synagogue with his guide dog.
Rav Moshe Feinstein - The Precedent from the Yerushalmi
Rav Moshe Feinstein (Teshuvot Igrot Moshe Orach Chayim 1:45), in response to a question sent to him by Rav Pinchas Teitz of Elizabeth, New Jersey, also permitted a blind man to enter the synagogue with his guide dog. Rav Moshe cited the Jerusalem Talmud (Megillah 3:3), which states:
Rabi Yehoshua ben Levi states that synagogues and study halls are built to be used by Talmud scholars [to eat and drink there]... Rabi Imi instructed the teachers of youngsters [who were present in the synagogue during the course of the day] to permit even a marginal scholar to enter the synagogue with his donkey and his tools [or clothes].
The Yerushalmi regards permitting an animal to enter a synagogue or study hall to be no more disrespectful to the sanctity of these places than eating or drinking in them. Hence, argues Rav Feinstein, just as the practice has developed to permit eating and drinking in the synagogue, at the very least in case of urgent need, so too an animal should be permitted to enter the synagogue in case of urgent need. Even though these actions constitute disrespect for the synagogue, they are permitted since synagogues outside of Israel are built on the condition that their sanctity does not forbid their use for mundane purposes in case of urgent need. Enabling a blind person to attend the synagogue most certainly constitutes urgent need, insists Rav Feinstein, and accordingly, a guide dog may be brought by its blind master into the synagogue.
Rav Feinstein also suggests (although he expresses some hesitation concerning this line of reasoning) that bringing an animal into the synagogue for mundane purposes (such as protecting the animal from theft) undoubtedly constitutes an expression of dishonor to the sanctity of the synagogue. However, when an animal is brought into the synagogue to enable a blind person to pray with the community, no disrespect is shown toward the holiness of the synagogue.
According to this approach, one would be permitted to bring a guide dog even into synagogues in Israel (which are not built with a stipulation to permit mundane activities to take place within them). However, Rav Feinstein expresses reservations regarding this line of reasoning and stops short of asserting that his lenient ruling also applies to Israeli synagogues. According to Rav Soloveitchik's approach to this issue, though, a blind person may bring a guide dog into a synagogue even in Israel.
Dissenting Views--Chelkat Yaakov, She’arim Metzuyanim BeHalachah, and Rav Kasher
However, two other prominent rabbis argue that a guide dog may not be brought into the synagogue. Rav Yaakov Breisch (Teshuvot Chelkat Ya’akov, Orach Chayim 34) and Rav Shlomo Braun (She’arim Metzuyanim BeHalachah 13:2) cite Chatam Sofer’s assertion (Teshuvot Chatam Sofer, Orach Chayim 31) that if Jews permit a particular activity in synagogue that non-Jews forbid in their place of worship, it would constitute a desecration of God’s name. Hence, they argue, since non-Jews do not permit animals in their houses of worship, it would be a desecration of God’s name to permit a guide dog in the synagogue.
Regardless of the merits of this argument, it appears to be factually incorrect. In fact, the various Christian denominations in this country do not have a policy forbidding a blind person to enter their houses of worship with a guide dog. This was confirmed in conversations I conducted in 1992 with the National Council of Churches, the Chancery of the Roman Catholic Diocese of New York, and the Guide Dog Foundation for the Blind. I called Rav Braun (Rav Breisch was already deceased at the time) who told me that he was unaware that Church policy had changed to permit guide dogs to enter their houses of worship.
Rav Breisch’s other criticisms of Rav Feinstein’s responsum include concern that a guide dog will disrupt prayer services. However, those familiar with seeing-eye dogs report that these animals are well trained and are very unlikely to cause a disruption. Rav Breisch also writes that he cannot imagine why there is no alternate means of enabling a blind person to attend the synagogue. The fact is, however, that there is a training period in which the dog and the blind individual must be together at all times. Though Rav Breisch has other criticisms of Rav Moshe’s responsum, Rav Feinstein’s argument appears far more persuasive than that of Rav Breisch.
Another prominent Rav who forbids guide or service dogs from entering a Beit Kenesset is Rav Menachem Mendel Kasher. Rav Kasher (Torah Sheleimah XV, p. 147) points out that the Torah (Devarim 23:19) forbids one to offer a sacrifice that was purchased with money acquired from the sale of a dog. Accordingly, Rav Kasher asserts, it is certainly forbidden to bring a dog into the Beit HaMikdash. Rav Kasher argues that since many early authorities consider the sanctity of the synagogue to be of biblical origin and similar to the sanctity of the Temple, then just as one is forbidden to bring a dog into the Beit HaMikdash, so too one is forbidden to bring a dog into the synagogue.
One may respectfully question Rav Kasher's argument. The fact that an activity is forbidden in the Beit HaMikdash does not at all imply that it is forbidden in a Beit Kenesset. The laws regarding the sanctity of the Temple differ from those regarding the sanctity of the synagogue. Many activities are forbidden in the Temple and yet are permissible in the synagogue, such as wearing shoes (see Berachot 62b). Furthermore, Rav Kasher does not prove that one is forbidden to bring a very well-disciplined guide dog into the Beit HaMikdash.
The Opinion of Rav Ovadia Yosef and his Family
Halachic practice of a Sephardic synagogue is impacted greatly by the rulings of Rav Ovadia Yosef and his family. Although Rav Yitzchak Yosef (Yalkut Yosef 151:25) writes that it is preferable to refrain from bringing a guide dog into a Beit Kenesset, Rav Ovadia’s grandson, Rav Yaakov Sasson, writes (Halachah Yomit November 30, 2016): “if the dog is quiet and well-behaved in the synagogue and the congregants are not frightened by its presence, there is no reason to prevent a blind man from coming to the synagogue and bringing his seeing-eye dog along with him.”
Modern Orthodox Jews, generally speaking, are comfortable with dogs. They are certainly comfortable with handicapped individuals bringing guide or service dogs into their homes. As such, it is entirely appropriate for a Rav to follow the rulings of Rav Feinstein, Rav Soloveitchik (as reported by his leading student and son-in-law Rav Lichtenstein), and Rav Teitz to permit a guide or service dog to enter a Beit Kenesset. I have seen this work out exceedingly well and it was very well-received in practice in two communities--the synagogue in which I was raised, Congregation Beth Judah of Brooklyn, New York, and Congregation Shaarei Orah of Teaneck, New Jersey, where I have the honor of serving as Rav. This is a ruling which is well-founded in the Gemara and Posekim, endorsed by three of the greatest authorities of the twentieth century, and very much works in practice. It should be followed in practice in our community.
 Rav Lichtenstein’s second Yahrtzeit is observed this week.
 We should note that other leading students of Rabbi Soloveitchik recall that he believed it to be forbidden to bring a guide dog into a synagogue.
 We should note that based on this Gemara and its application by Rav Soloveitchik, one should not bring one’s winter coat or rain coat into a Beit Kenesset, since one would hang it up before entering a home.
 Rav Pinchas Teitz’ son and successor, Rav Elazar Meyer Teitz, told me that his father concurred with Rav Moshe’s ruling and implemented it in practice.
 For a discussion and summary of the issue, see Bi’ur Halachah, 151:11 s.v. Aval
 Despite the fact that the sanctity of the synagogue is similar to that of the Temple, the intensity of their respective levels of sanctity differs. Rambam expresses this distinction by stating (Hilchot Tefillah 11:5) that a Beit Kenesset must be treated with respect (Kavod), as opposed to the Temple (Hilchot Beit Habechirah 7:1), towards which we must maintain an attitude of awe (Yirah). Rav Soloveitchik explains that the distinction derives from the fact that the Beit HaMikdash is Hashem's home in which we are visitors, in contradistinction to the synagogue which is our home in which God (so to speak) is a visitor (see Shi’urim LeZeicher Abba Mori Zal, pp. 63-65). Halachic authorities differ as to the extent that various laws regarding the Beit Kenesset should be extrapolated from the laws of the Beit HaMikdash. See Teshuvot HaElef Lecha Shlomo, Orach Chayim 76, Teshuvot Binyan Tziyon 9, Teshuvot Meishiv Davar 2:14, and Rav Herschel Schachter, Eretz HaTzvi pp. 93-94.