Owning a Dog
וּלְכֹל בְּנֵי יִשְׂרָאֵל לֹא יֶחֱרַץ כֶּלֶב לְשֹׁנוֹ (Shemos 11:7)
Is it permitted to own a dog?
The Gemara tells us several times that it is forbidden to own or raise a "bad dog in one's house," explaining that it may bite or injure people, cause a woman to miscarry with its frightening barking, keep away the poor, and minimize one's yiras Shamayim (by "replacing" the mezuzah as a guard for the home). In Bava Kama 79b, the Mishnah rules that one may keep a dog only if it is chained. Shulchan Aruch (Choshen Mishpat 409:3) rules this way, i.e., that one may keep a dog chained with metal, and this will avoid biting and prevent miscarriages, which are attributed to fear. One who lives in a border city, which is considered dangerous, may release the dog at night for protection. The Rama adds that all cities among the goyim are considered dangerous, but nevertheless, it is forbidden to keep a "bad" dog. Yaavetz says that all dogs are treated equally, and one should be machmir about the sakanah of owning dogs.
What about specialized dogs?
The poskim say that one should definitely not own more dogs than needed—one is enough for security; two or more would only be needed for a farmer or the like, who uses them to control livestock. The Yaavetz explicitly forbids "expensive short-haired dogs," which are commonly show dogs and the like. He considers it moshav leitzim and maaseh erev-rav to be busy with such sport and breeding. It is permitted to own a Seeing Eye dog, and even to bring it to shul, but it should be left in a place where it will not disturb people.
What are the halachos of feeding one's dog?
While one must feed his farm animals before eating himself, this likely does not apply to a dog—but it is good to be machmir. A dog may be fed tarfus but not issur hana'ah.
What halachos apply on Shabbos?
All living creatures are muktzeh on Shabbos. This includes dogs, and includes ruffling the dog's hair or moving it. The Mishnah Berurah and Eliya Rabbah dispute whether that issur may be violated to rescue an animal from a situation of tza'ar ba'alei chaim. There is a common misconception that one's own dog is not muktzeh to him. This error perhaps derives from the halachah that one may feed his own dog, but not stray dogs.
One may walk a dog on Shabbos without an eruv and may hold the leash. The leash may not hang to within a tefach of the ground, nor may more than a tefach hang out of the back of his hand. When tying the leash on, avoid a forbidden knot, and make sure not to lean on the dog, because that would be under the prohibition of riding an animal on Shabbos.
What halachos apply to mad dogs?
A dog acting oddly may have rabies, which is a deadly disease. Such dogs may be killed or captured on Shabbos because of sakanah. A stray dog that bit someone may be captured on Shabbos to test for rabies.
May a dog do melachah?
A Jew must ensure that his animals "keep" Shabbos. A dog may not carry for you or wear name tags or decorations that are not clothing in the street without an eruv. Rav Tzvi Pesach Frank was asked about a dog that was trained to turn a light on and off at a signal from the owner, and he forbade doing so on Shabbos.
May a dog be spayed?
It is forbidden to spay or neuter male or female dogs.