Before Islam, it was common for Arabs to keep dogs, and people were used to having them around. When the Prophet Muhammad (peace be upon him) came, he ordered people to get rid of dogs to discourage keeping them. This order was only temporary, and later it was canceled. After that, the Prophet (peace be upon him) said it was okay to keep dogs for three specific reasons: hunting, guarding crops, and protecting herds. (If your home is unsafe, keeping a dog for security is also okay.) Keeping dogs for other reasons is not allowed.

The Prophet Muhammad (peace be upon him) said that angels of mercy do not enter a house if it has pictures or dogs.

In another saying, the Prophet (peace be upon him) mentioned that if someone keeps a dog for any reason other than guarding livestock, crops, or hunting, they lose a part of their daily reward.

So, aside from these three reasons, keeping a dog isn’t allowed.