The superstition of a dog howling at night is that it is a warning of death. This superstition is thought to have originated in ancient times, when dogs were often used as guard animals. If a dog howled at night, it was thought to be a warning that someone was approaching or that there was some other danger. Over time, this superstition came to be associated with death, as it was believed that the dog was howling in warning of someone's impending demise.
In some cultures, it is believed that a dog howling at night is a sign that a person's soul is leaving their body. In other cultures, it is believed that a dog howling at night is a sign that a person is about to die. Whatever the specific meaning of the superstition, it is clear that there is a widespread belief that a dog howling at night is a sign of bad luck or death.