Behaviour itself is made up of many things including genetics, the environment, previous learning and experiences. It is shaped by individual personalities, breed characteristics, and past interactions. Dog reactivity can be caused by these and often a combination of things.
The emotions a dog experiences can range from excitement and frustration to nervousness and fear. In many cases, the dog has learnt to show this behaviour because it will result in them getting what they want. For example, if your dog is allowed to greet other dogs after pulling towards them, they have learnt that this behaviour works to greet other dogs. It may look like your dog is ‘desperate’ to get to other dogs and super frustrated if they can’t. The frustration may be expressed by barking/whining. On the other hand, if your dog is fearful or uncomfortable being around other dogs, and they bark, pull and lunge at other dogs to make the other dog go away, your dog learns that these behaviours can work to get other dogs to move away from them.
Find out more about why dogs react, what it means, and how you can help in our full article on Reactivity In Dogs here.