All dogs have them, some more pronounced than others.

A dog’s hackles run from the back of the neck to the base of the tail.

Dogs have special muscles in their skin that are attached to their hair follicles, these muscles are capable of fluffing the coat by trapping air between the hair shafts.

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 an unfamiliar sound or a fright is experienced the body prepares for action!

Dogs undergo what is called a fight or flight response to certain stimuli. By definition, it is a physiological reaction when a dog feels threatened. He will either stay and ‘fight’ or he’ll take aversive action by ‘flight’ (run away).

When a dog’s fight or flight response is activated, it is theorized, adrenaline is released into the body along with stress hormones. The body gets a boost of energy, the heart rate picks up and hackles are raised to communicate arousal.

For many owners, the raising of the fur along a dog’s back and shoulders is cause for alarm. It’s almost always associated with aggression, however, depending on the environment, the situation and the dog’s body language, this is not always the case.

This behaviour is often seen in young dogs that are unsure of how to act when startled in their environment.
 Raising the hackles makes a dog appear larger and therefore more intimating to an approaching dog.

This same function is also seen sometimes in cats when they have been startled.

  These hackles are displaying lack of confidence and fearful.

   Two patches of hackles on show, unpredictable, be aware of engagement.

  These hackles exhibit a high level of confidence, generally associated with aggression.