Puppies go through multiple socialisation and fear periods during their development.

The primary socialisation period most people are aware of occurs from approximately 3 to 12 weeks of age, which coincides with the first fear period. However, socialisation and training do not end in early puppyhood

Dogs go through an additional developmental stage, the second fear period, once they are a teenager. This stage can be especially confusing and frustrating for a dog owner because it may seem like your puppy has forgotten everything they have learnt, is unable to settle down or seems scared of things that they previously coped with perfectly fine.

This second fear period is a temporary and normal developmental stage. Your dog is not deliberately trying to be difficult or disobedient, and this important period is manageable.

What is a fear period

A fear period is a time when dogs are more sensitive and aware of the world around them. Essentially your dog’s ‘danger brain’ activates more readily, even to very minor triggers. They may be more concerned about new objects or experiences, and even things that they previously liked can become stressful or anxiety-inducing.

Fear periods are a normal part of puppy development designed to help dogs learn what they should be afraid of and what they should avoid for survival.

When do fear periods occur?

Dogs experience two main fear periods in their lives. The first fear period occurs at 8-11 weeks of age when puppies are starting to explore the world and are meeting new people and animals.

The second fear period occurs between 6 and18 months of age, depending on the dog’s growth and development This is typically around the time the dog reaches sexual maturity and is becoming more independent. Small breed dogs usually go through this stage at a younger age than larger breed dogs.

The duration of this fear period is variable between individual dogs, but it can last up to 2-3 weeks. Your pet may experience multiple fear periods over this timeframe, with some dogs experiencing these more often.

Why does the second fear period happen?

The second fear period is believed to be linked to the hormonal and neural developments that occur in dogs as they reach sexual maturity. These changes affect the dog’s brain chemistry, making them more aware of potential threats and more cautious about new situations.

The second fear period is also influenced by the dog’s social maturation, which is the process of learning how to interact with other dogs and humans. During this time, some dogs become shyer, while others become more confident.

How can I tell if my dog has entered their second fear period?

How a second fear period manifests can vary between dogs. Some dogs may show only mild signs of fear, while others may become very anxious and reactive. This could include being scared of new objects, people or animals and being unsure about new situations.

Some common signs of fear and anxiety in dogs include:

  • Barking, growling, or snapping at unfamiliar people, animals, or objects
  • Hiding, trembling, or cowering behind the owner or under furniture
  • Refusing to walk past or approach something that scares them
  • Showing signs of stress, such as panting, drooling, yawning, or licking their lips
  • Becoming more clingy or needy, or more aloof or independent
  • Having toileting accidents in the house or showing other signs of training regression

How to help your dog through their adolescent fear period

Be patient and understanding

This fear period may be frustrating, but it’s a normal part of your puppy’s development and can have a big impact on their future behaviour. Be patient with them. Don’t force or lure your dog to approach something that scares them. Let them decide how close they want to get and reward them for any progress they make.

Proactively plan training sessions

Don’t change your dog’s routine or environment too much, as this can add to their stress and uncertainty. Keep your dog’s schedule, rules, and expectations as stable as possible and try to avoid exposing them to too many new or overwhelming things all at once. Negative experiences at this stage can shape their future reactions to similar scenarios and lead to future anxiety issues.

Create as many positive experiences for your dog as possible. Instead of surprise, unplanned encounters, expose your puppy to new and/or scary things in a controlled and positive way. For example, if your puppy is scared of the vacuum cleaner, you can start by turning it on in another room and give them treats as they stay calm to help build more positive associations with the sound. As they get used to it, gradually bring it closer to your puppy over time and keep up the rewards.

Stay positive and reassuring

Keep things positive and fun. If your puppy is scared or anxious, try to comfort them and make them feel safe. It is absolutely fine to provide a stressed or anxious dog reassurance in these moments. Don’t scold or punish your dog for being afraid, as this will only make them more fearful and insecure. Instead, be calm and supportive, and praise your dog for being brave and confident.

Remember it’s okay to ask for help

If your puppy’s fear period is particularly severe, you might need some professional help.

Petbarn’s dog training classes aren’t just for young puppies. There are also classes for older dogs that cover things from basic commands to more advanced tricks. These classes allow your dogs to socialise in a group in a safe and controlled environment, and the experienced trainers are there to help guide you and provide strategies to help you and your dog get through this challenging period.

Enrol your puppy in Petbarn's Puppy School

If your puppy’s second fear period is causing them significant distress or anxiety, you should talk to your local Greencross Vets for advice. Your veterinarian will be able to offer medical options and behavioural advice that might help manage your dog’s behavioural challenges, as they work through this fear period. They could also offer a referral to a veterinary behavioural specialist or trainer if needed.


The second fear period is a normal and natural part of your dog’s development. The challenges you’ll face during this period don’t mean that your adolescent dog is broken or that you failed as an owner. With your love and support, your puppy will get through this stage and become a more confident and well-adjusted adult dog.