What is the ruling on keeping dogs in gardens or homes with the intention of guarding, and how should they be treated, and what should one do if touched by their nose or saliva?

The basic principle regarding keeping dogs is prohibition, except when there is a need. It is permissible to keep them for guarding livestock, crops, and for hunting. Scholars have differed on the permissibility of keeping them for guarding homes and gardens, and the preponderant opinion is that it is permissible. As for how to interact with the dog, it should not enter the house or mix with its occupants; rather, it should be kept in its designated guarding place, fed, and watered. If a person is touched by dog saliva or its waste, it must be washed seven times, one of which is with earth or soap.