Dog hackles are hairs on a dog’s back, running from the neck between the shoulders along the spine to the base of the tail. They occasionally rise due to piloerection, a sympathetic nervous system response similar to that which causes human goosebumps. Raised hackles are involuntary and typically indicate some kind of stress.

Hackles are the hairs that run along a dog’s spine. They typically begin at the neck and extend to a dog’s tail. Below a dog’s skin are muscles that are attached to his or her hackles. These muscles are called arrector pili (Byer).

All dogs have hackles, whether you’ve seen them raised or not. They run all the way from a dog’s neck, along the back to the base of the tail. When a dog’s hackles rise, it is an involuntary reaction to something in the environment. It’s a bit like us getting goosebumps when hearing a great piece of music or see something emotional.

Hackles are the group of hairs that stand up along a dogs neck and back caused by a fear response or to show dominance over another animal. Dogs aren’t the only species that have hackles. Birds have hackles around their necks and erect their feathers when they are asserting dominance.