Dogs make a variety of sounds to express different wants, needs and feelings, but a dog's howl, in particular, is unmistakable. The reason for his howling, on the other hand, is typically less clear. So why exactly does a dog howl? We've got the lowdown.

Howling is a deeply ingrained behavior. A dog's howl, similar to a wolf's, is a loud, drawn-out, mournful cry. It differs from a bark, which is typically brief and explosive.
A dog may howl for some of the same reasons wolves do. However, as dogs have evolved and grown closer to humans, some of their reasons for howling may have also evolved. Here are several reasons why your dog might howl:
As a response to noise: Your dog may howl in response to a nearby siren, a musical instrument, a sound on the television or your own singing. While this may mean he's protesting because he dislikes the noise, it could just as easily mean he likes it and wants to join in!You'll also probably notice that your dog likes to tilt his head to the sky to let out this vocalization. There are a variety of reasons why dogs will tilt their heads, but there is little information on why dogs might "howl at the moon." Many people speculate that this is because it straightens out the vocal cords and provides more airflow from the chest to allow them to provide this type of vocalization. Others speculate that it allows the sound waves to travel further, allowing more dogs or creatures know they are there.