Nicola’s Guide to Surviving the ‘Teenage’ Phase
May 18, 2026
Has your once ‘perfect’ puppy suddenly stopped listening? Has your sweet kitten become unpredictable or aloof? Pets absolutely go through puberty! While we don’t usually see them dealing with teenage acne, they undergo a massive surge of hormones like humans do — in the veterinary world, we call this the adolescent phase.
During puberty — the period when they reach sexual maturity and become capable of reproducing — hormonal changes affect the brain, influencing confidence, impulse control and social behaviour. This can temporarily undo weeks or months of good training.
Below, you’ll find Vet Nicola’s tips to help you understand the biology behind the adolescent phase, and respond with patience rather than frustration. Have a read through and don’t hesitate to contact us at Avenues Vets for more advice.
Ask us for tailored advice for your teenage pet
Surviving the ‘teenage’ phase: supporting your pet’s development
Why behaviour can change
Nicola explains that in dogs, adolescence often occurs between 6–18 months (depending on breed). Hormonal shifts can increase independence, distractibility and risk-taking behaviour. That reliable recall can suddenly become selective.
In cats, puberty can bring territorial behaviours such as spraying, roaming attempts, vocalising or tension with other household pets. These behaviours are driven by natural instincts linked to maturity.
This isn’t them being difficult on purpose. During puberty, the brain undergoes a process called synaptic pruning, essentially rewiring itself. During that transition, their focus shifts from ‘please my owner’ to ‘explore the world and find a mate’. The key message from Nicola is that this phase is developmental, not defiance.
When does it happen?
The timing of the adolescent phase depends heavily on the species and, in the case of dogs, the breed size. Our vets in Glasgow often advise owners to expect variation between individuals:
- Cats: Usually starts between 4 and 6 months.
- Small Dogs: Around 6 to 9 months.
- Large/Giant Dogs: Can start as late as 12 to 18 months.
What actually happens?
Just like in humans, the ‘primitive’ part of the brain (the amygdala, which handles emotions) develops much faster than the ‘rational’ part (the prefrontal cortex, which handles decision-making and impulse control).
| The Human Version | The Pet Version |
|---|---|
| Mood swings | Sudden selective deafness (ignoring commands they used to know) |
| Testing boundaries | Challenging the rules of the house or becoming more territorial |
| Growth spurts | Physical clumsiness as their limbs grow faster than their coordination |
| Hormonal drive | Roaming, “mounting” behaviour, or scent marking (spraying) |
Supporting your adolescent dog
Consistency is everything. Reinforce boundaries calmly and clearly. If recall slips, go back a step and use long leads and controlled environments to rebuild reliability.
Mental stimulation becomes just as important as physical exercise around Lanarkshire. Puzzle feeders, scent games and short, structured training sessions help channel teenage energy constructively. Nicola recommends avoiding overwhelming situations and focusing on positive reinforcement.
Remember, large-breed dogs may mature more slowly. What looks like stubbornness is often an immature brain still learning impulse control.
Supporting your adolescent cat
For cats, neutering plays an important role in managing hormone-driven behaviours such as spraying and roaming. It can significantly reduce stress-related territorial behaviours whilst removing the risk of unwanted litters. Provide vertical space, scratching posts and predictable routines to help your cat feel secure. If tensions arise between cats in the household, ensure multiple feeding, watering and litter stations to reduce competition.
Patience wins
The adolescent phase can feel challenging, but it is temporary. Our vet Nicola suggests calm, consistent guidance and positive reinforcement help your pet develop into a well-adjusted adult. Avoid punishment-based approaches, which can increase anxiety during this sensitive developmental window.
Hormones, growth spurts and even underlying discomfort can all influence behaviour.If you’re unsure whether behaviour changes are purely developmental or linked to health, our vets in Glasgow are here to help.
Book an adolescent health check at Avenues Vets to review your pet’s development, discuss neutering where appropriate, and get tailored advice to navigate this important life stage with confidence.
