Do angels enter a house with a dog?

What the hadith says

Abu Talha reported that he heard the Prophet ﷺ say that angels of mercy do not enter a house in which there is a dog or a picture of a living creature (Sahih al-Bukhari 3225). Similar narrations appear in several other places in the collections.

Which angels are meant?

Scholars explain that this refers to the angels who bring mercy and blessing, who visit homes. It does not mean the angels who record deeds, nor those who protect a person, because these stay with every human being everywhere. See Who are the Kiraman Katibin? and Do Muslims believe in angels?

Which dogs does it apply to?

The Muslim position on dogs is not simply "never". Many scholars hold the following:

• A dog kept without need as a pet is what the warning applies to in the strictest reading. Some scholars treat it as disliked, and others as forbidden.
• Working dogs kept for guarding, herding or hunting are generally permitted, according to other authentic hadith.
• A dog outside the house, such as a guard dog in a yard, is treated differently from one kept inside.

Scholars and schools differ on the strictness and on whether a pet dog for companionship counts as a need. Some modern scholars allow dogs for needs like security, and for people who need an assistance dog. If you want a specific ruling for your situation, ask a trusted imam. See Can I keep my dog after becoming Muslim?

What if I already have a dog?

If you have a dog and are new to Islam, there is no need to panic or rush to get rid of it. A pet is a responsibility, and Islam teaches kindness to animals. Think about the decision calmly, ask a knowledgeable person, and make sure the dog is well cared for in any case. Do not mistreat, abandon or harm it.

Is the dog itself bad?

No. Dogs are Allah's creation and Islam commands kindness to them. The hadith is about the household's blessing, not about the dog being evil. See Will my dog go to heaven in Islam?