What is the ruling on keeping a dog, and what kind of kindness is required towards dogs in Islam?

Summary

According to the majority of scholars, keeping a dog is prohibited unless there is a need permitted by Islamic law, namely hunting, guarding crops and protecting livestock. Most scholars classify the dog as a severe impurity (mughallazah), so a vessel licked by a dog must be washed seven times, with one wash using soil. Even so, dogs fall within the duty of ihsan, so they must not be wronged, tortured or neglected. Local custom should be considered to avoid slander and misunderstanding, but it cannot override clear textual evidence.

Written in our own words from the original fatwa — check the source before acting on it.