What is the ruling on buying and selling dogs?

It is forbidden to own and sell dogs, even those that are permissible to own, according to the authentic prophetic hadiths. Owning a dog results in a reduction of two qirats from one's reward daily, except for hunting dogs, and dogs for guarding livestock and crops. As for selling a dog, it is invalid, and its price is forbidden according to the majority of scholars.

Some have made an exception for hunting dogs, but the hadiths that permit their sale are weak. If a person is compelled to buy a dog for guarding or hunting and cannot find one except through purchase, then it is permissible for him to buy it. The sin falls upon the seller, and the price should be taken from him whenever possible.